Prefix meanings

Letters that can be added to the beginning of another word to change the meaning.
Prefix Meaning Examples
A, An without, lack of, not amoral, acellular, abyss, achromatic, anhydrous
Ab, Abs away, from, separated absent , abhor , abstract
Acro height, high, tip, end acrophobia, acrobat
Alt tall, high altitude, alto, altimater
Ambi, Amphi both, around, combining from amphitheater, amphibian, ambivalent, ambidextrous
Ante before, earlier, in front of antecedent, antedate, antemeridian, anterior
Anti against, opposite of anticlimax. antiaircraft, antiseptic, antibody
Auto self, same autopilot, autobiography, automobile, autofocus
Baro weight barometer, barograph
Bene good, well benefit, benediction
Bio life biology, biography, biopsy
Cap head cap, captain, capital
Capt take, receive capture, capitivity, captivate
Circum around, about circumvent, circumnavigate, circumscribe
Class class, group classify, classical, classic
Co, Com, Con with, together connect, contain , comply , concentrate
Contra, Contro against, opposite contradict, contrast, contrary, controversy
De off, away from, down from, reverse, remove, out of, derived from devalue, deactivate, debug, degrade, deduce,descend , decide
Dent tooth dentist, dental
Di, Dif, Dis separation, negation, apart, in different directions: discharge , dismember , dislike , disappear, disagreeable
Ego I egotistic,ego, egocentric
Em, empt by, obtain exempt, emptor, preempt
Esth feeling esthetic, esthete
En put into, cover with enclose, entangle, enslave, encase
Ex out of, from, former extract, exhale, excavate, ex-president
Extra beyond, outside, more than extracurricular, extramarital, extravagant , extraordinary
Fac make, do factory, facsimile
Flor flower flora, florist, floral
Fract, frag break fraction, fracture, fragile
Gen race, birth generation, genetics, genocide
Grat please, thank grateful, gratitude, gratis
Gran grain grain, granary, grange
Heli sun helium, heliograph
Hetero different, other heterosexual, heterodox, heterogeneous
Homo, Homeo same, alike homonym, homophone, homeostasis, homosexual
Hum earth, soil humus
Hyper over, more, beyond hyperactive, hypersensitive, hypercritical
Ident same identify, identity, identical
Il, Im, In, Ir not, without illegal, immoral, injustice, irresponsible, impossible, inconsiderate
inter between, among intersect, interstellar, intervene, interpenetrate
Intra, Intro within, inside intravenous, intragalactic, introvert
Journ daily journal, journey, journalism
Jus law, right just, justice
Liber free liberty, liberal
Lingu tongue linguistics, lingual
Loc place local, location, localize
Luna moon lunar, lunatic
Macro large, prominent macroeconomics, macrostructure, macrocosm
Mad middle medium, mediate
Magni great magnify, magnitude
Micro very small microscope, microcosm, microbe
Mis wrongly / not misunderstand , misfire , misgivings
Miss send, let go mission, missionary, missile
Mono one, single, alone monocle, monologue, monogamy, monotony
Mot move motion, motor
Multi many multiple, multitask
Nav ship navy, navigate, naval
Non, Un not, without nonsense , nonsmoker , unkind , unravel
Numer number numeral, numerator, numerous
Ob, o, oc, against, over, completely object, occur, omit, oppose
Omni all, every omniscient, omnivorous, omniscient, omnidirectional
Op, opt sight optic, optical, optometrist
Ora speak, pray oral, oracle, orator
Par give birth parent, parentage
Peri around peripheral, periscope
Poly many polygamous, polygon
Post after, behind postmortem, posterior, postscript, postoperative
Pre, Pro before, forward precede, predict, project, prologue
Quad four quadriplegic, quadrangle
Que ask query, questionnaire
Re, Retro backwards, back, again retrograde , review , revision
Rota wheel, round rotate, rotary, rotor
Sacr holy sacrament, sacred
San healthy, sound sanity, sanitation, sane
Sci know science, scientific
Semi half of , partially semiannual , semicircle, semiannual, semiconscious
Sub under, lower submarine, subsidiary, substandard
Super, Supra above, excessive superlative, suprarenal
Syl, Sym, Syn same time, together,united symmetry, symposium, synchronize, synapse
Tele distant telephone, telegraph, television
Tra, Trans across, beyond, through transmit, transaction, translation, transfer, transgress
Tri three, every third tricycle, trimester, triangle, triathlon
Turb whirling, turmoil turbine, turbid, turbulent
Ultra beyond. excessive ultraliberal, ultrasonic
Urb city urban, urbane
Un not, lacking, opposite of unfinished, unskilled, ungraceful, unfriendly
Uni one, single unicorn, unicellular, unicycle, unilateral
Vaca, vacu empty, hollow vacant, vaccum, vacate
Val strong, worth valid, valetudinarian
Ven sale vend, vendor, venel
Vis see vision, visualize, visible
Vit live vitamin, vital, vitality
Zo animal zoo, zoologist, zodiac