CAD comes from the Latin verb cadere, "to fall." Thus, a cascade is usually a waterfall, but sometimes a flood of something else that seems to pour on top of you: a cascade of new problems, a cascade of honors, and so on.

e.g. cadaver, decadent, cadence, cadenza

TRIB comes from the Latin tribuere, meaning "to give" or "to pay." So a group that distributes food passes it out to those in need, and when you contribute to the group you give your money or energy to it.

e.g. tribute, tributary, attribute, retribution

TEN/TENU comes from the Latin tenuis, meaning "thin." So to entend something is to stretch it, and lots of things get thin when they're stretched. The ten- root is even seen in pretend, which once meant to stretch something out above or in front; that something came to be a claim that you were something that you actually weren't.

e.g. tenuous, attenuated, extenuating, distended

DERM comes from the Greek derma, meaning "skin." For medical advice on a skin problem such as acne, we may go to a dermatologist, or skin specialist. When we get a shot, it's usually with a hypodermic, a needle that goes "under the skin". A pachyderm is a "thick-skinned" animal, which most of us just call an elephant.

e.g. dermal, epidermis, taxidermist, dermatitis

ENDO comes from the Greek endon, meaning "within." In English it appears almost always in scitific terms, especially in biology. A nonscientific endo- word is endogamy, meaning marriage within a specific group as required by custom or law - one of the many customs that can be seen everywhere from the most remote tribes to the highest society in wealthy countries.

e.g. endocrine, endodontic, endogenous, endorphin

NECRO comes from the Greek nekros, meaning "dead body," so it's not surprising that it shows up in some unappetizing places. A necrophagous insect, for instance, is one that feeds on dead bodies; when homicide investigators discover a corpse, they may use the insect evidence to figure out when the person died.

e.g. necrosis, necromancer, necropolis, necropsy

TOM comes from the Greek root meaning "cut." Thus, the Latin word anatomia, from which we get anatomy, means "dissection" - that is cutting or separating the parts of an organism for detailed examination. In a labotomy, the nerves linking a brain lobe to the rest of the brain are removed; even though lobotomies have hardly been performed in the last 50 years, the idea can still fill us with horror.

e.g. appendectomy, gastrectomy, tonsillectomy, mastectomy

IATR, from the Greek iatros, "healer, physician," usually hides in the middle of words, where it isn't immediately noticed. A pediatrician treats children. A psychiatrist is a phisician who treats mental problems. (A psychologist, by contrast, doesn't have a medical degree and thus can't prescribe drugs.) And a physiatrist is a doctor who practices "physical medicine and rehabilitation," which may involve such things as testing various physical abilities, relieving pain through electric heat or massage, or training patients to exercise or to use an artificial limb.

e.g. iatrogenic, bariatric, geriatric, podiatrist

OID comes from the Greek word for "appearance" or "form." Since aster in ancient Greek meant "star," the small bodies orbiting between Mars and Jupiter that looked like stars through primitive telescopes were called asteroids. A factoid is a little bit of information that looks like a fact, whether it is or not. And some people these days will attach -oid to just about anything; you can probably figure out the meaning of nutsoid, nerdoid, and freakazoid without much help.

e.g. dendroid, humanoid, rhomboid, deltoid

SCOP, which usually appears in a suffix, comes from the Greek skopein, meaning "to look at." In English we have the simple noun scope, along with some other words it sometimes stands for: telescope, microscope, periscope, and so on. And have you ever used a stereoscope, a device your great-grandparents probably enjoyed, which lets you look through a viewer at two slightly different photographs of the same thing, one with each eye, to enjoy the illusion that you're seeing it in three dimensions?

e.g. endoscope, arthroscopic, laparoscopy, oscilloscope

STRAT comes from the Latin word stratum, meaning "spread" or "bed." Strata, a form of the same word, came to be used by the Romans to mean "paved road" - that is, street.

e.g. stratum, stratification, substrate, stratocumulus

LATER comes from the Latin adjective lateralis, meaning "side." The noun for side in Latin was latus, and the same word served as an adjective meaning "wide." The relationship between the two isn't hard to spot, since something wide extends far out to its sides. So lines of latitude extend east-west around the earth, in the dimension we tend to think of as its width (unlike lines of longitude, which extend north-south, in the dimension that, for some reason, we decided to think of as its "length").

e.g. lateral, bilateral, collateral, equilateral

PAR, from the Latin, means "equal." Our English word par means an amount taken as an average or a standard, and especially the standard score for each hole on a golf course - which is why the phrase "par for the course" means "about as well as expected." We compare things to see if they're equal; similar things can be called comparable - that is, "equal with." And "on a par with" means "comparable to."

e.g. parity, disparity, nonpareil, subpar

PHOB comes from the Greek noun phobos, "fear," and it shows up clearly in out noun phobia, meaning "unusual fear of a specific thing." Phobias vary greatly in seriousness and also in frequency. Most of us have experienced claustrophobia, at some time, but few truly suffer from fear of the number 13,?a condition known as triskaidekaphobia.

e.g. acrophobic, agoraphobia, hemophilia

ITIS, a suffix found both in Greek and Latin, means "disease" or "inflammmation." In appendicitis your appendix is swollen and painful, and in tonsillitis the same is true of your tonsils. With laryngitis, your throat and larynx may become so sore that it's difficult to talk. Some of us enjoy making up our own -itis words; high-school teachers, for example, long ago noticed that many of their seniors tended to lose all interest in schoolwork and start skipping classes, and labeled the condition senioritis.

e.g. bursitis, hepatitis, bronchitis, tendinitis

MUR, from the Latin noun murus, meaning "wall," has produced a modest number of English words.

e.g. muralist, intramural, immure, extramural

ONYM comes from the Greek onyma, meaning "name, word." An anonymous donor or writer is one who isn't named. A synonym is a word with the same meaning as another word. And homonyms are words that look and sound alike but aren't actually related, such as well ("healthy") and well ("a deep hole with water in it").

e.g. antonym, patronymic, pseudonym, eponymous

LOQU comes from the Latin verb loqui, "to talk." An eloquent preacher speaks fluently, forcefully, and expressively. And a dummy's words come out of a ventriloquist's mouth - or perhanps out of his belly (in Latin, venter).

e.g. colloquium, soliloquy, colloquial, loquacious

VIR is Latin for "man." A virtue is a good quality - originally, the kind of quality an ideal man possessed. And virtuous behavior is morally excellent. All in all, the Rmans?seem to have believed that being a man was a good thing.?

e.g. virility, triumvirate, virago, virtuosity

VAL has as its basic meaning "strength," from the Latin verb valere, meaning "to be worthy, healthy, or strong" and "to have power or inluence." So evaluating?a house involves determining how healthy it is. A valid license or credit card is one that's?still in effect, and a valid proof is one that provedes strong evidence.

e.g. valor, equivalent, prevalent, validate

CRE/CRET comes from the Latin verb crescere, which means both "to come into being" and "to grow." So a crescendo in music occurs when the music is growing louder, and a decrescendo when it's growing softer.

e.g. crescent, accretion, excrescence, increment

FUS comes from the Latin verb fundere, "to pour out" or "to melt." A fuse depends on melting metal to break an overloaded circuit. Nuclear fusion involves the "melting" together of light nuclei to form heavier nuclei, and fusion cuisine brings together the cooking of two or more cultures.

e.g. transfusion, suffuse, effusive, profusion

POT comes from the Latin adjective potens, meaning "able." Our English word potent means "powerful" or "effective,"?whether for good or bad. A potent new antibiotic might be able to deal with infections that have developed resistance to older drugs; an industrial gas might be identified as a potent contributor to climate change; and a potent drink might leave you staggering.

e.g. potential, potentate, impotent, plenipotentiary

MAND comes from mandare, Latin for "entrust" or "order." A command is an order; a commandment is also an order, but usually one that comes from God. And a commando unit carries out orders for special military actions.

e.g. mandate, mandatory, commandeer, remand

UND comes into English from the Latin word unda, "wave," and undare, "to rise in waves,"?"to surge or flood." Undulations are waves or wavelike things or motions, and to undulate is to rise and fall in a wavelike way.

e.g. undulant, inundate, redound, redundancy

GRAT comes from the Latin words gratus, meaning "pleasing, welcome, or agreeable," and gratis, meaning "grace, agreeableness, or pleasantness." A meal that served graciously will be received with gratitude by grareful guests; those who show no appreciation could be called ingrates.

e.g. gratify, gratuity, gratuitous, ingratiate

CRAC/CRAT comes from the Greek word meaning "power." Attached to another root, it indicates which group holds the power. With demos, the Greek word for "people," it forms democracy, a form of government in which the people rule. A theocracy, from the Greek theos, "god," is government based on divine guidance. In a meritocracy, people earn power by their own merit.

e.g. aristocrat, bureaucrat, autocratic, plutocracy

PUNC comes from the Latin noun punctum, meaning "point." A period is a form of punctuation that's literally a point, and a punctured tire has been pricked by a sharp point.

e.g. punctilious, acupuncture, punctual, compunction

CLUS comes from the Latin claudere, "to close." Words based on the Latin verb often have forms in which the d?becomes an s. So, for example, include, which once meant "to shut up or enclose" and now means "to contain," has the elated word inclusive, which means "including everything."

e.g. occlusion, exclusive, recluse, seclusion

PLAC comes from the Latin placere, "to please or be?agreeable to," or placare, "to soothe or calm." Pleasant, pleasurable, and pleasing all derive from this root, even though their spelling makes it hard to see.

e.g. placate, placebo, placidity, implacable

PROP/PROPRI comes from the Latin word proprius, meaning "own." A proprietor is an owner, and property is what he or she owns. And the original meaning of proper was "belonging to oneself," so a writer around the year 1400? could say "With his own proper sword he was slain," even if we might not say it quite the same way today.

e.g. proprietary, propriety, appropriate, expropriate

TORT comes from a form of the Latin verb torquere, meaning "to twist, wind, or wrench." In torture, parts of the body may be wrenched or twisted or stretched; so those "Indian sunburns" that schoollikds give by twisting in different directions on some unlucky guy's wrist stay pretty close to touture's original meaning.

e.g. tort, extort, contort, tortuous

VIV comes from vivere, the Latin verb meaning "to live or be alive." A survivor has lived through something terrible. A revival brings something back?to life, whether it's an old film, interest in a long-dead novelist, or religious enthusiasm in?a group, maybe in a huge tent?in the countryside.

e.g. vivacious, bon vivant, revivify, vivisection

ACER/ACR comes from the Latin adjective acer, meaning "sharp" or "sour." Grapefruit and limes have an acid taste; acid can also describe a person's sense of humor (other words for it maght be sharp or biting.) The acidity of the soil often indicates wheteher it's good for growing certain crops; blueberries, for instance, love acid soil, so they're more likely to be found east of the Mississippi River, where acid soil is the rule.

e.g. acerbic, acrid, acrimony, exacerbate

META is a prefix in English that generally means "behind" or "beyond." In medicine, for example, the metacarpal bones are the hand hones that come right after, or beyond, the carpal or wrist bones. And metalanguage is language use to talk about language, which requires going beyond normal language.?

e.g. metadata, metaphorical, metaphysics, metonymy

PREHEND/PREHENS comes from the Latin verb prehendere, "to seize." Most of the English words where it appears are closely related to the ones discussed below.

e.g. prehensile, apprehend, comprehend, reprehensible

PURG comes from the Latin verb purgare, "to clean or cleanse." Almost all the English words where it shows up are closely related to those discussed below.

e.g.??purge, expurgate, purgative, purgatory

PATER/PATR comes from both the Greek and the Latin word for "father." So a patron, for example, is someone who assmes a fatherly role toward an institution or project or individual, giving moral and financial support.

e.g. patrician, patriarchy, expatriate, paternalistic

LEGA comes from the Latin legare, meaning "to appoint" or "to send as a deputy." The same root actually shows up in such words as legal - but how the law connects with sending deputies can get awfully compliated and probably isn't worth going into.

e.g. legate, legacy, delegation, relegate

GREG comes from the latin grex, "herd" or "flock." Bees, starlings, cows - any creatures that like to live together in flocks or herds - are called gregarious, and the same word is used for people who enjoy companionship and are happiest when they're in the middle of a rowdy herd.

e.g. aggregate, congregation, egregious, segregate

FLU comes from the Latin verb fluere,? "to flow." So a flume is a narrow gorge with a stream flowing through it. A fluent speaker is one from whom words flow easily.?Influence originally referred to an invisible fluid that was believed to flow from the stars and to affect the actions of humans. A mysterious outbreak of disease in 15th-centure Italy led Italians to blame it on the stars' influenza?- and the name stuck.

e.g. affluence, effluent, confluence, mellifluous

DEC comes from both Greek and Latin and means "ten." So a decade lasts for ten years; the decimal system is based on ten; and a decahedron is a geometrical shape with ten sides.

e.g. decalogue, decathlon, decibel, decimate

NOM comes from the Latin word for "name." A nominee is a person "named" - or nominated - to run for or serve in office. A binomial ("two names") is the scientific name for a species: Felis catus for the house cat, for?example. A polynomial, with "many names," is an algebra expression involving several terms: 2x2+9y-z3, for instance.

e.g. nominal, nomenclature, ignominious, misnomer

JUR comes from the Latin verb jurare, "to swear, take an oath," and the noun jus, "right or law." A jury, made up of jurors, makes judgments based on the law. And a personal injury was originally something done to you that a court would find unjust.

e.g. jurisprudence, abjure, perjury, de jure

PENT comes from the Greek word for "five." The pentagon in Washington, D.C., the world's largest office building, has five sides just like any other pentagon. And a pentatonic scale in music has only five notes, rather than the seven notes of the major or minor scale.

e.g. pentathlon, Pentateuch, pentameter, Pentecostal

QUINT comes from the Latin word meaning "five." Quintuplets are babies that come in sets of five; about 60 U.S. families increase in size by that number every year.

e.g. quincentennial, quintessential, quintet, quintile

GEN, which comes from the Greek genos, meaning "birth," has generated dozens of English words. A set of genes, for instance, gives birth to a living being. And a genealogy is a historical map of your family, showing how each generation gave birth to the next.

e.g. genesis, generator, genre, carcinogenic

MUT comes from the Latin mutare, "to change." Plenty of science-fiction movies - Godzilla, The Fly, The Incredible Shrinking Man - used to be made on the subject of weird mutations, changes in normal people or animals that usually end up causing death and destruction. What causes the unfortunate victim to mutate may be a mysterious or alien force, or perhaps invisible radiation. Though the science in these films isn't always right on target, the scare factor of an army of mutants can?be hard to beat.?

e.g. commute, immutable, permutation, transmute

PHIL comes from the Greek word meaning "love." In philosophy, it's joined with sophia, "wisdom," so philosophy means literally "love of wisdom." When joined with biblio-, "book," the result is bibliophile, or "lover of?books." And Philadelphia, containing the Greek word adelphos, "brothers," was named by its Quaker founder, Willian Penn, as the city of "brotherly love."

e.g. oenophile, philatelist, Anglophile, philanthropy

IDIO comes from the Greek?idios, meaning "one's own" or "private." In Latin this root led to the word?idiota, meaning "ignorant person" - that is, a person who doesn't take in knowledge from outside himself. And that led to a familiar English word that gets used too often, usually to describe people who aren't ignorant at all.

e.g. idiom, idiomatic, idiosyncrasy, idiopathic

TEXT comes from a Latin verb that "to weave." So a?textile?is a woven or knitted cloth. The materail it's made from determines its?texture, the smoothness or roughness of its surface. And individual words are "woven" into sentences and paragraphs fo form a text.

e.g. textual, context, hypertext, subtext

SANCT, meaning "holy," comes from the Latin word?sanctus. Thus,?sanctity?means "holiness." In ancient Greece, a spot could be?sanctified, or "made holy," by a group of priests who carried out a solemn ritual;?these might be spots where fumes arose from a crack in the earth or?where a spring of clear water flowed out of the ground, and a temple might be built there for worship of a god.

e.g. sanction, sanctimonious, sacrosanct, sanctuary

STRU/STRUCT comes from the Latin verb?struere, meaning "to put together, build, arrange." A?structure?is something that's been constructed, - that is, built or put together.?Instructions?tell how the pieces should be arranged. Something that?obstructs?is a barrier that's been "built" to stand in your way. And something?destructive?"unbuilds."

e.g. deconstruction, infrastructure, construe, instrumental

CONTRA is the Latin equivalent of?anti-, and it too means essentially "against" or "contrary to." A?contrast?"stands against" something else that it's compared to. And?contrapuntal?music, as in the music of Bach, sets one memlody against anohter played at the same time and produces harmony (which no one is opposed to).

e.g. contraband, contraindication, contravene, contrarian

SERV means "to be subject to." A?servant?is the person who serves you with meals and provides other necessary services. A tennis or volleyball?serve?puts the ball in play, much as a servant puts food on the table.

e.g. serviceable, servile, servitude, subservient

PER is a Latin preposition that generally means "through," "throughout",?or "thoroughly."?Thus,?perforate?means "to bore through,"?perennial?means "throughout the years," and?permanent?means "remaining throughout." And the "thoroughly" sense shows up in?persuade, for "thoroughly advise," and?perverted, "thoroughly turned around."

e.g. percolate, pervade, permeate, persevere

PARA is a Greek prefix usually meaning "beside" or "closely related to." So?parallel?lines run beside each other. And a Greek?paragraphos?was originally a line written beside the main text of a play to show where a new person begins speaking; today we just start a new paragraph on a new line.

e.g. paraphrase, paralegal, paramedic, paramilitary

HYPER is a Greek prefix that means "above or beyond," so?hyper-?often means about the same thing as super-.?Hyperinflation?is inflation that 's growing at a very high rate. To be?hypercritical?or?hypersensitive?is to be critical or sensitive beyond the normal. And if you?hyperextend?a knee or elbow, it means you're actually bending it backward.

e.g. hyperacitve, hyperbole, hypertension, hyperventilate

TEMPER comes from the Latin verb?temperare, "to moderate or keep within limits" or "to mix." Most of the world's people live in the?temperate?zone - that is, the zone where the?temperature?is moderate, between the hot tropics and the icy Arctic and Antarctic Circles. It's less easy to see how we get?temperature?from this root;?the word actually used to refer to the mixing?of different basic elements in the body, and only slowly came to mean how hot or cold that body was.

e.g. temper, temperance, intemperate, distemper

MILL means either "a thousand" or "a thousandth." A?millennium?is a thousand years, and a?million?is a thousand thousands. But a?milligram?is a thousandth of a gram, a?milliliter?a thousandth of a liter, and a?millimeter?a thousandth of a meter.

e.g. millefleur, millenarianism, millipede, millisecond

NEG and its variants?nec-?and?ne-?are prefixes of denial or refusal in Latin, and the Latin verb?negare?measn "to say no." To?negate?something is to make it?ineffective, and something?negative?denies, contradicts, refuses, or reverses.

e.g. negligent, abnegation, negligible, renege

CENT, from the Latin?centum, means "one hundred." A dollar is made up of a hundred?cents, though other monetary systems use?centavos?or?centimes?as the smallest?coin. A?centipede?has what appears to be a hundred feet, though the actual number varies greatly. But there really are a hundred years in a?century.

e.g. centenary, centigrade, centimeter, centurion

FRACT comes from the Latin verb?frangere, "to break or shatter." A?fraction?is one of the pieces into which a whole can?be broken, and a?fracture?is a break in a wall, a rock, or a bone.

e.g. fractious, fractal, infraction, refraction

TELE has as its basic meanings "distant" or "at a distance." A?telescope?is for looking at far-off objects; a camera's?telephoto?lens magnifies a distant scene for a photogragh; and a?telivision?lets us watch things taking place far waay.

e.g. telegenic, teleological, telemetry, telecommute

FUNCT comes from the Latin verb?fungi, "to perform, carry out." If your car is?functional, it's able to perform its?function?of providing transportation. But a?functional illiterate?is a person who, for all practical or functional purposes, might as well not be able to read or write at all.

e.g. functionary, malfunction, defunct, dysfunctional

STRICT comes from the Latin verb meaning "to draw tight, bind, or tie." So the English word?strict?means "tightly controlled." And when someone begins a sentence "Strictly speaking, ..." you know he or she is going to be talking abtou a word or idea in its most limited sense, "drawing tight" the meaning till it's as narrow as possible.

e.g. stricture, restrictive, constrict, vasoconstrictor

CLAM/CLAIM comes from the Latin verb?clamare, meaning "to shout or cry out." To?claim?often means "to call for." And an?exclamation?is a cry of shock, joy, or surprise.

e.g. clamor, procliam, acclamation, declaim

VERB comes from the Latin?verbum, meaning "word." A?verb?- or action word - appears in some form in every complete sentence. To express something?verbally?- or to?verbalize?something - is to say it or write it.

e.g. verbose, proverb,?verbatim, verbiage

SCRIP/SCRIB comes from the Latin verb?scribere, "to write."?Scribble?is an old word meaning to write or draw carelessly. A written work that hasn't been published is a?manuscript. And to?describe?is to picture something in words.

e.g. conscription, circumscribe, inscription, proscibe

SIMIL/SIMUL come from the Latin adjective?similis, meaning "like, resembling, similar," and the verb?simulare, "to make like." Two?similar?things resemble each other. Two?simultaneous?activities proceed at the same time. And a?facsimile, such as you might receive from your?fax?machine, looks exactly the same as the original.

e.g. simile, assimilate, simulacrum, simulate

SCEND comes from the Latin verb?scandere, "to climb." The staircase we?ascend?to our bedroom at night we will?descend?the next morning, since what goes up must come down.

e.g. transecnd, ascendancy, condescend, descendant

POLIS/POLIT comes from the Greek word for "city." The ancient Greek city-states, such as Athens, Thebes, and Sparta, operated much like separate nations, so all their?politics?was local, like all their public?policy?- and even all their?police!

e.g. politic, politicize, acropolis, megalopolis

FALL comes from the Latin verb?fallere, "to deceive." It's actually at the root of the word?false, which we rarely use today to mean "deceptive," though that meaning does show up in older phrases: "Thou shalt not bear false witness against thy neighbor," for instance, or "A false-hearted lover will send you to your grave."?Fallere?is even at the root of fail and fault, though you might not guess it to look at them.

e.g. fallacy, infallible, fallacious, fallibility

SOLU comes from the Latin verb?solvere, "to loosen, free, release,"?and the root therefore may take the form?solv-?as well. So to?solve?a problem means to find its?solution, as if you were freeing up a logjam. And a?solvent?is a chemical that?dissolves?or "loosens up" oil or paint.

e.g. soluble, absolution, dissolution, resolute

NANO comes from the Greek?nanos, meaning "dwarf." For a prefix meaning "small," English got by for centuries with the Greek?micro-, and later?mini-?came to be used widely as well. But only recently, as a result of advances in scientific knowledge and technology, has there been a need for a prefix meaning "extremely small" - a need that's been filled by?nano-, which today is being attached to all kinds of words, sometimes not very seriously (nanoskirt, nanobrained, etc.)

e.g. nanotechnology, nanosecond, nanostructure, nanoparticle

SURG comes from the Latin verb?surgere, meaning "to rise, spring up." Our noun?surge?means "a sudden, large increase," and the verb?surge?means "to move with a surge." A?storm surge?occurs when violent storm winds at sea cause the water to pile up higher than normal sea level. A?surge protector?keeps a spike in electrical current from "frying" your computer when a lighting strike sends a sudden surge down the wires.

e.g. upsurge, insurgency, counterinsurgent, resurgent

ARM comes from the Latin?arma, meaning "weapons, tools." The root is seen in such English words as?arms?(i.e. weapons),?armed, and?army. It has nothing to do with the limb that starts at your shoulder; the name for that kind of arm comes from the Latin word meaning "shoulder."

e.g. armada, armistice, armory, disarming

NUL/NULL comes from the Latin word?nullus, "none," which is itself a combination of?ne-?("not") and?ullus?("any"). Have you ever noticed how many of our negative words start with?n-? Think of?no, not, never, nothing, none, no one, nowhere, and the hundreds of?non-?words - just about all of which go back to the same Greek root.

e.g. null, nullify, nullity, annulment

HYDR flows from the Greek word for "water." The "water" root can be found in the lovely flower called the?hydrangea: its seed capsules resemble ancient Greek water vessels.

e.g. hydraulic, hydroelectric, hydroponics, dehydrate

TRANS comes from Latin to indicate movement "through, across, or beyond" something.?Translation?carries a writer's?meaning from one language to another. A television signal is sent or?transmitted?through the air (or a cable) to your set. When making your way through a city on public?transportation, you may have to?transfer?from one bus or subway to another.

e.g. transient, transfiguration, transponder, transcendent

MEDI comes from the Latin?medius, meaning "middle." Our word?medium?refers to something in a middle position. The?medieval?period of European history, also known as the Middle Ages, is the period between Greek and Roman antiquity and the "modern age." But why people around 1620 began to use the term "Middle Ages," because they regarded themselves as modern, is an interesting question.

e.g. median, mediate, intermediary, mediocrity

PRO is an important prefix, with a couple of quite different broad meanings. In this section, we'll look at words in which?pro-?has the basic meaning "for" or "favoring." Everyone knows words like?pro-democracy?and?pro-American, but other?pro-?words may not be quite so self-explanatory.

e.g. proactive, pro bono, proponent, pro forma

PRO, in its other broad meaning, means "before, in front of." So, for example, to proceed means "to move out in front"; to progress means?"to move forward"; and somebody prominent stands out, as if he or she were actually standing out in front of the crowd.

e.g. protrude, prophylaxic, promulgate, prologue

AUT/AUTO comes from the Greek word for "same" or "self." Something?automatic?operates by itself, and an?automobile?moves by itslf, wothout the help of a horse. An?autograph?is in the handwriting of the person him- or herself, and an?autopsy?is an inspection of a corpse by an examinder's own eyes.

e.g. automaton, autonomy, autism, autoimmune

PALEO comes from the Greek?palaios, meaning "ancient" - that is, "older than old." The prefix sometimes gets attached to very recognizable words;?paleobiology, for instance, deals with the biology of fossil organisms,?paleogeography?is the study of geography in earlier geological eras, and?paleoecology?is the study of the relationship of plants and animals to their environment in those eras.

e.g. Paleolithic, paleography, paleontology, Paleozoic

CIRCU/CIRCUM comes from the Latin circus, meaning "circle." So a?circus?is traditionally held under a round tent. A?circuit?can be a tour around the area or territory, or?the complete path of an electric current. To circumnavigate means "to navigate around" - often around the world.?

e.g. circuitous, circumference, circumspect, circumvent

SYN is a Greek and Latin prefix meaning "together" or "at the same time." So "in?sync" (short for "in?synchronization") means "together in time." And a?synonym?is a word that can be considered together with another word since it has the same meaning.

e.g. syntax, synthesize, synergy, syndrome

TOXI comes from the Greek and Latin words for "poison," something the Greeks and Romans knew a good deal about. Socrates died by taking a solution of poison hemlock, a flowering plant much like wild carrot that now also grows in the U.S. Rome's enemy Mithridates, king of Pontus, was obsessed with poisons, experimented with them on prisoners, and tried to make himself immune to them by eating tiny amounts of them daily. Nero's mother Agrippina poisoned several of her son's rivals to power - and probably did the same to her own husband, the emperor Claudius.

e.g. toxin, toxicity, toxicology, neurotoxin