Prefix Meaning Example Comments a- "not" asymmetric, "not symmetric" a- before consonants, an- before vowels acro- "high" acrophobia, "fear of heights" (more) allo- "other" allotransplantation, "transplant of tissue from another person" (more) an- "not" aneuploid, "not euploid" a- before consonants, an- before vowels ante- "before" antebellum, "before a war" anti- "against" anti-inflammatory, "against inflammation" (more) auto- "self" automobile, "moves itself" (more) bi- "two" bicentennial, "two centuries" See number prefixes in English co- "together" cooperation, "working together" contra- "against" contraindication, "against indication" (more) counter- "against" countermeasure, "action against" (more) de- "negative, remove" deactivate, "stop from working" di- "two" diatomic, "two atoms" See number 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- "on, above" epidural, "outside the dura mater" (more) extra- "outside" extracellular, "outside a cell" (more) hemi- "half" hemisphere, "half of a sphere" (more) See number prefixes in English hexa- "six" hexagon, "six-sided polygon" (more) See number prefixes in English hyper- "a lot"; "too much" hypercalcemia, "too much calcium in the blood" (more) See hyper hypo- "a little"; "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" *******, "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" macroeconomics, "workings of entire economies" (more) mal- "bad", "wrong" malocclusion, "bad occlusion" (more) maxi- "big", "as big as possible" maxi-single, "single with extras" (more) meso- "middle" mesoamerican, "middle of the Americas" (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) See number 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) See number prefixes in English over- "excess", "too much"; "on top" overexpression, "too much expression" overcoat, "outer coat" (more) pan- "all" pancytopenia, "low counts across all cell types" pan-American, "involving all of the Americas" (more) Sometimes "all-" is used, especially in Asian English, where All-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, or federal (in the case of federations). 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) See number 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- "in favor of" pro-science, "in favor of science" (more) proto- "first"; "primitive"; "precursor" Proto-Indo-European, "precursor of Indo-European" (more) pseudo- "false", "specious" pseudonym, "fake name" (more) quadri- "four" quadrilateral, "four-sided" (more) See number 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 as unselfconscious) semi- "partial"; "somewhat"; "half" semiarid, "somewhat arid" (more) See number 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) See number 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) In plain English
Answers & Comments
Prefix Meaning Example Comments a- "not" asymmetric, "not symmetric" a- before consonants, an- before vowels acro- "high" acrophobia, "fear of heights" (more) allo- "other" allotransplantation, "transplant of tissue from another person" (more) an- "not" aneuploid, "not euploid" a- before consonants, an- before vowels ante- "before" antebellum, "before a war" anti- "against" anti-inflammatory, "against inflammation" (more) auto- "self" automobile, "moves itself" (more) bi- "two" bicentennial, "two centuries" See number prefixes in English co- "together" cooperation, "working together" contra- "against" contraindication, "against indication" (more) counter- "against" countermeasure, "action against" (more) de- "negative, remove" deactivate, "stop from working" di- "two" diatomic, "two atoms" See number 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- "on, above" epidural, "outside the dura mater" (more) extra- "outside" extracellular, "outside a cell" (more) hemi- "half" hemisphere, "half of a sphere" (more) See number prefixes in English hexa- "six" hexagon, "six-sided polygon" (more) See number prefixes in English hyper- "a lot"; "too much" hypercalcemia, "too much calcium in the blood" (more) See hyper hypo- "a little"; "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" *******, "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" macroeconomics, "workings of entire economies" (more) mal- "bad", "wrong" malocclusion, "bad occlusion" (more) maxi- "big", "as big as possible" maxi-single, "single with extras" (more) meso- "middle" mesoamerican, "middle of the Americas" (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) See number 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) See number prefixes in English over- "excess", "too much";
"on top" overexpression, "too much expression"
overcoat, "outer coat" (more) pan- "all" pancytopenia, "low counts across all cell types"
pan-American, "involving all of the Americas"
(more) Sometimes "all-" is used, especially in Asian English, where All-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, or federal (in the case of federations). 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) See number 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- "in favor of" pro-science, "in favor of science" (more) proto- "first"; "primitive"; "precursor" Proto-Indo-European, "precursor of Indo-European" (more) pseudo- "false", "specious" pseudonym, "fake name" (more) quadri- "four" quadrilateral, "four-sided" (more) See number 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 as unselfconscious) semi- "partial"; "somewhat"; "half" semiarid, "somewhat arid" (more) See number 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) See number 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) In plain English