| Prefix | Meaning | Example | Comments |
|---|
| a- | "not" | asymmetric, "not symmetric" | takes the form an- beforevowels; seeprivative alpha |
| acro- | "high" | acrophobia, "fear of heights" (more) | |
| allo- | "other" | allotransplantation, "transplant of tissue from another person" (more) | |
| alter- | "other" | alter ego, "other personality" (more) | |
| ante- | "prior" | antebellum, "before a war" | |
| anti- | "opposite" | anti-inflammatory, "against inflammation" (more) | |
| auto- | "by oneself or itself" | automobile, "moves itself" (more) | |
| bi- | "two" | bicentennial, "consisting of or occurring every two centuries" binomial, "two terms" | Seenumber prefixes in English |
| co- | "together" | cooperation, "working together" | takes the form con- before vowels |
| cis- | "on the same side" | cisgenesis, "genes don't change within breeding and birth setting" | |
| contra- | "below" ; "against" | contraindication, "against indication" (more) | |
| counter- | "against" | countermeasure, "action against" (more) | |
| de- | "negative, remove" | deactivate, "stop from working" | |
| di- | "two" | diatomic, "two atoms" dipole, "two poles" | Seenumber prefixes in English |
| dis- | "negative, remove" | disappear, "vanish" (more) | |
| down- | "down"; "reduce" | downshift, "shift to a lower gear"
downregulation, "regulation toward lessened expression" (more) | |
| dys- | "negative, badly, wrongly" | dysfunction, "bad function" (more) | |
| epi- | "upon addition" , "above" | epidural, "outside the dura mater" (more) | |
| extra- | "to a greater extent" ; "beyond" | extracellular, "outside a cell" (more) | |
| fore- | "before" | foresight, "seeing beforehand" (more) | |
| hemi- | "half" | hemisphere, "half of a sphere" (more) | Seenumber prefixes in English |
| hexa- | "six" | hexagon, "six-sided polygon" (more) | Seenumber prefixes in English |
| hyper- | "beyond" | hypercalcemia, "too much calcium in the blood" (more) | Seehyper |
| hypo- | "marginal"; "not enough" | hypokalemia, "not enough potassium in the blood" (more) | |
| ig- | "not" | ignoble, "not noble"
ignorant, (from roots meaning) "not knowing"
(more) | ig- (before gn- or n-), il- (before l-), im- (before b-, m-, or p-), in- (before most letters), or ir- (before r-) |
| il- | "not" | illegal, "not legal" (more) | ig- (before gn- or n-), il- (before l-), im- (before b-, m-, or p-), in- (before most letters), or ir- (before r-) |
| im- | "not" | imbalance, "lack of balance" (more) | ig- (before gn- or n-), il- (before l-), im- (before b-, m-, or p-), in- (before most letters), or ir- (before r-) |
| in- | "not" | inactive, "not active" | ig- (before gn- or n-), il- (before l-), im- (before b-, m-, or p-), in- (before most letters), or ir- (before r-) |
| infra- | "below" | infrared, "below red on the spectrum" (more) | |
| inter- | "between" | interobserver, "between observers" (more) | |
| intra- | "within" | intracellular, "inside a cell" (more) | |
| ir- | "not" | irregular, "not regular" (more) | ig- (before gn- or n-), il- (before l-), im- (before b-, m-, or p-), in- (before most letters), or ir- (before r-) |
| macro- | "large-scale" ; "exceptionally prominent" | macroeconomics, "workings of entire economies" (more) | |
| mal- | "unpleasant", "not" | malocclusion, "bad occlusion" (more) | |
| maxi- | "big", "as big as possible" | maxi-single, "single with extras" (more) | |
| meso- | "middle" | mesoamerican, "middle of the Americas" (more) | |
| meta- | "self-referential" | metadata, "data that provides information about other data" (more) | |
| micro- | "small-scale" | micrometer, "small-measurement instrument" (more) | |
| mid- | "middle" | midportion, "middle part" (more) | |
| mini- | "small" | miniature, "small"; "smaller version" (more) | |
| mis- | "bad", "wrong" | misspelling, "incorrect spelling" (more) | |
| mono- | "one" | monotheism, "belief in one god" (more) | Seenumber prefixes in English |
| multi- | "many", "more than one" | multiplex, "many signals in one circuit" (more) | |
| non- | "no", "not" | nonstop, "without stopping" (more) | |
| octo- | "eight" | octopus, "eight-footed" (more) | Seenumber prefixes in English |
| over- | "excess", "too much";
"on top" | overexpression, "too much expression"
overcoat, "outer coat" (more) | |
| pan- | "all" | pancytopenia, "low counts across all [blood] cell types"
pan-American, "involving all of the Americas"
pansexual, "sexually attracted to people of all genders" (more) | Sometimes "all-" is used, especially in Asian English, whereAll-Union was a standard translation of the Russian word meaning "pan-USSR" or "USSR-wide", and "All-India" is a similar standard term in India, comparable to words such asnational,nationwide, orfederal (in the case offederations). |
| para- | "beside"; "beyond"; "related to"; "altered" | paranormal, "beyond the normal"
paresthesia, "altered sensation"
paramilitary, "military-like" (more) | |
| penta- | "five" | pentateuch, "the five books of Moses" (more) | Seenumber prefixes in English |
| per- | "through"; "throughout" | percutaneous, "through the skin" (more) | |
| peri- | "around" | pericardial, "around the heart" (more) | |
| poly- | "many" | polyglot, "many languages" (more) | |
| post- | "after" | postoperative, "after surgery" (more) | |
| pre- | "before"; "already" | preassembled, "already built" (more) | |
| pro- | "on behalf of" ; "before" | pro-science, "in favor of science" (more) | |
| proto- | "first"; "primitive"; "precursor" | Proto-Indo-European, "precursor of Indo-European"
prototype, "first or prime example" (more) | |
| pseudo- | "false", "specious" | pseudonym, "fake name" (more) | |
| quadri- | "four" | quadrilateral, "four-sided" (more) | Seenumber prefixes in English |
| quasi- | "somewhat", "resembling" | quasiparticulate, "resembling particles" (more) | |
| re- | "again" | reestablish, "establish again" (more) | |
| self- | "[acting on or by] oneself" | self-cleaning, "cleans itself" (more) | By normative convention, always hyphenated (except for a few multiprefix compounds such asunselfconscious) |
| semi- | "partial"; "somewhat"; "half" | semiarid, "somewhat arid" (more) | Seenumber prefixes in English |
| sub- | "below" | subzero, "below zero" (more) | |
| super- | "above"; "more than"; "great" | supermarket, "big market" (more) | |
| supra- | "above" | supraorbital, "above the eye sockets" (more) | |
| tetra- | "four" | tetravalent, "four valence electrons" (more) | Seenumber prefixes in English |
| trans- | "across"; "connecting" | transatlantic, "across the Atlantic Ocean" (more) | |
| tri- | "three" | tripartite, "three parts" (more) | |
| ultra- | "beyond"; "extremely" | ultraviolet, "beyond violet on the spectrum" (more) | |
| un- | "not"; "remove"; "opposite" | unopened, "not opened" (more) | |
| under- | "beneath"; "not enough" | underexposure, "not enough exposure" (more) | |
| up- | "up"; "increase" | upshift, "shift to a higher gear"
upregulation, "regulation toward increased expression" (more) | |
| xeno- | "foreign" | xenophobia, "fear of strangers or foreigners"
xenotransplantation, "transplant from another species" (more) | |
