A prefix  is placed at the beginning of a word to modify or change its meaning. This is a list of the most common prefixes in English, together with their basic meaning and some examples. You can find more detail or precision for each prefix in any good dictionary.
A prefix  goes at the beginning of a word. A suffix goes at the end of a word.
The origins of words are extremely complicated. You should use this list as a guide only, to help you understand possible meanings. But be very careful, because often what appears to be a prefix is not a prefix at all. Note also that this list does not include elements like "auto-" or " bio-", because these are "combining forms", not prefixes.
| prefix | meaning | examples | |
|---|---|---|---|
| a- | also an- | not, without | atheist, anaemic |
| a- | to, towards | aside, aback | |
| in the process of, in a particular state | a-hunting, aglow | ||
| a- | of | anew | |
| completely | abashed | ||
| ab- | also abs- | away, from | abdicate, abstract |
| ad- | also  a-, ac-, af-, ag- al-, an-, ap-, at- as-, at- | movement to, change into, addition or increase | advance, adulterate, adjunct, ascend, affiliate, affirm, aggravate, alleviate, annotate, apprehend, arrive, assemble, attend |
| ante- | before, preceding | antecedent, ante-room | |
| anti- | also ant- | opposing, against, the opposite | anti-aircraft, antibiotic, anticlimax, Antarctic |
| be- | all over, all around | bespatter, beset | |
| completely | bewitch, bemuse | ||
| having, covered with | bejewelled | ||
| affect with (added to nouns) | befog | ||
| cause to be (added to adjectives) | becalm | ||
| com- | also  co-, col-, con-, cor- | with, jointly, completely | combat, codriver, collude, confide, corrode |
| contra- | against, opposite | contraceptive | |
| counter- | opposition, opposite direction | counter-attack, counteract | |
| de- | down, away | descend, despair, depend, deduct | |
| completely | denude, denigrate | ||
| removal, reversal | de-ice, decamp | ||
| dia- | also di- | through, across | diagonal |
| dis- | also di- | negation, removal, expulsion | disadvantage, dismount, disbud, disbar |
| en- | also em- | put into or on | engulf, enmesh |
| bring into the condition of | enlighten, embitter | ||
| intensification | entangle, enrage | ||
| ex- | also  e-, ef- | out | exit, exclude, expand |
| upward | exalt, extol | ||
| completely | excruciate, exasperate | ||
| previous | ex-wife | ||
| extra- | outside, beyond | extracurricular | |
| hemi- | half | hemisphere | |
| hyper- | beyond, more than, more than normal | hypersonic, hyperactive | |
| hypo- | under | hypodermic, hypothermia | |
| in- | also  il-, im- | not, without | infertile, inappropriate, impossible |
| also  il-, im-, ir- | in, into, towards, inside | influence, influx, imbibe | |
| infra- | below | infrared, infrastructure | |
| inter- | between, among | interact, interchange | |
| intra- | inside, within | intramural, intravenous | |
| non- | absence, negation | non-smoker, non-alcoholic | |
| ob- | also  oc-, of-, op- | blocking, against, concealing | obstruct, occult, offend, oppose |
| out- | surpassing, exceeding | outperform | |
| external, away from | outbuilding, outboard | ||
| over- | excessively, completely | overconfident, overburdened, overjoyed | |
| upper, outer, over, above | overcoat, overcast | ||
| peri- | round, about | perimeter | |
| post- | after in time or order | postpone | |
| pre- | before in time, place, order or importance | pre-adolescent, prelude, precondition | |
| pro- | favouring, in support of | pro-African | |
| acting for | proconsul | ||
| motion forwards or away | propulsion | ||
| before in time, place or order | prologue | ||
| re- | again | repaint, reappraise, reawake | |
| semi- | half, partly | semicircle, semi-conscious | |
| sub- | also  suc-, suf-, sug-, sup-, sur-, sus- | at a lower position | submarine, subsoil |
| lower in rank | sub-lieutenant | ||
| nearly, approximately | sub-tropical | ||
| syn- | also sym- | in union, acting together | synchronize, symmetry |
| trans- | across, beyond | transnational, transatlantic | |
| into a different state | translate | ||
| ultra- | beyond | ultraviolet, ultrasonic | |
| extreme | ultramicroscopic | ||
| un- | not | unacceptable, unreal, unhappy, unmanned | |
| reversal or cancellation of action or state | unplug, unmask | ||
| under- | beneath, below | underarm, undercarriage | |
| lower in rank | undersecretary | ||
| not enough | underdeveloped | ||
sources : Original Link