This list includes 51 Prefixes that start with A, from “a-” to “azo-“. Many come from Latin, Greek, or Old English and appear across science, medicine, and everyday speech.
Prefixes that start with A are short word parts added to roots to change or refine meaning. A notable example is “anti-“, a Greek-derived prefix that appears in politics, science, and general vocabulary.
Below you’ll find the table with Prefix, Origin, Meaning, Examples, and Notes.
Prefix: The prefix itself, shown in quotes where helpful, so you can spot the exact word part quickly.
Origin: Shows the prefix’s language source and brief history, helping you recognize patterns across words and languages.
Meaning: Gives a concise 3–7-word definition so you can grasp function without technical jargon.
Examples: Provides two to four clear example words so you can see real usage and form new vocabulary confidently.
Notes: Offers brief usage tips, variant forms, internal links, or topical notes that help you apply prefixes correctly.
Prefixes that start with A
| Prefix | Origin | Meaning | Example words |
|---|---|---|---|
| a– | Old English (pre‑900); Greek (classical) | not; on, in, at | amoral, afloat, atypical, afoot |
| ab- | Latin (classical) | away, from | absent, abduct, abjure |
| abs- | Latin (classical; variant of ab-) | away, off (before s) | abscond, absolve, abscess |
| ad- | Latin (classical) | to, toward, near | adapt, admit, adhere |
| ac- | Latin (classical; assimilated form of ad-) | to, toward (before c/k) | accept, accentuate, accommodate |
| af- | Latin (classical; assimilated form of ad-) | to, toward (before f) | affix, afford, afflict |
| ag- | Latin (classical; assimilated form of ad-) | to, toward (before g) | aggregate, aggravate, aggression |
| al- | Latin (classical; assimilated form of ad-) | to, toward (before l) | allocate, alleviate, alliance |
| an- | Greek (classical; also Latin assimilated ad-) | not, without; to, toward | anarchy, anaerobic, annex, announce |
| ana- | Greek (classical) | up, again, back, throughout | analysis, anachronism, anagram, anabolism |
| ambi- | Latin (classical) | both, on both sides | ambidextrous, ambivalent, ambigram |
| amphi- | Greek (classical) | both, around | amphibian, amphitheater, amphipathic |
| andro- | Greek (classical) | man, male | android, androgen, andrology |
| anthropo- | Greek (classical) | human, human-related | anthropology, anthropoid, anthropocene |
| anti- | Greek (classical) | against, opposed to | antibiotic, antifreeze, antisocial |
| ante- | Latin (classical) | before, preceding | antecedent, antebellum, antepenultimate |
| apo- | Greek (classical) | away from, separate | apology, apogee, apostate |
| arch- | Greek (classical) | chief, principal, extreme | archbishop, archrival, archipelago |
| archaeo- | Greek (classical) | ancient, primitive | archaeology, archaea, archaic |
| aero- | Greek (classical/late) | air, atmosphere | aeroplane, aerodynamics, aerospace |
| astro- | Greek (classical) | star, celestial | astronomy, astronaut, astrophysics |
| aster- | Greek (classical) | star-shaped, star | asterisk, asteroid, asterism |
| auto- | Greek (classical) | self, same | autobiography, autoimmune, autopilot |
| acro- | Greek (classical) | top, tip, extremity, high | acrobat, acropolis, acrophobia |
| actino- | Greek (classical) | ray, radiation, beam | actinometer, actinobacteria, actinic |
| acousto- | Greek (classical) | hearing, sound | acoustic, acoustics, acousto‑optic |
| adeno- | Greek (classical) | gland | adenoma, adenovirus, adenoid |
| agrí-/agri- | Latin (classical) | field, farming | agriculture, agronomy, agribusiness |
| agro- | Greek (classical) | field, soil, farming | agrochemical, agroecosystem, agrology |
| alb- | Latin (classical) | white, pale | albino, albedo, albaceous |
| allo- | Greek (classical) | other, different | allograft, allophone, allotrope |
| alto- | Italian/Latin (medieval/Renaissance) | high (pitch or altitude) | alto, altostratus, altocumulus |
| anaero- | Greek/modern scientific | without oxygen, lacking air | anaerobic, anaerobe, anaerobiosis |
| anemo- | Greek (classical) | wind | anemometer, anemone |
| angio- | Greek (classical) | vessel (usually blood vessel) | angioplasty, angiogram, angiosperm |
| apico- | Latin (classical) | tip, summit, apex | apical, apicoplast, apicectomy |
| audio- | Latin (classical) | hearing, sound | audio, audiology, audiophile |
| axio- | Greek (classical) | axis; worth, value | axiom, axiomatic, axiology |
| azo- | Neo‑Latin/Greek (19th c., chemistry) | nitrogen‑containing group | azo dye, azo compound, azotemia |
| auxo- | Greek (classical) | increase, growth | auxotroph, auxin, auxogenesis |
| athero- | Greek (classical) | gruel-like, fatty (plaque) | atherosclerosis, atheroma |
| axo- | Greek (classical) | axis, axle-like structure | axonal, axoplasm, axoneme |
| algo- | Greek (classical) | pain | algophobia, algometer, algalgia |
| antho- | Greek (classical) | flower | anthology, anther, anthocyanin |
| aqua- | Latin (classical) | water | aquarium, aqueduct, aquatic |
| atmo- | Greek (classical) | vapour, gas, air mass | atmosphere, atmospheric, atmometer |
| amylo- | Greek (classical) | starch | amylose, amylase, amyloid |
| anthrac- | Greek/Latin (classical) | coal, carbon, black | anthracite, anthrax, anthracolite |
| aleur- | Greek (classical) | flour, mealy | aleurone, aleuritic |
| alkalo- | Arabic/Neo‑Latin (17th–19th c.) | alkaline-like, nitrogenous base | alkaloid, alkaloidal |
| azo- (duplicate avoided) | — excluded duplicate entry to prevent repetition | — | — |
Descriptions
a–
Two historic senses: Old English “on/in” (afloat) and Greek negative “not” (amoral); extremely common and polyfunctional.
ab-
Latin prefix meaning “away” or “from”; frequent in legal, medical, and everyday vocabulary.
abs-
Variant of ab- occurring before s; shows regular assimilation in learned words.
ad-
Highly productive Latin prefix meaning motion/tendency toward; regularly assimilates to other consonants.
ac-
Form of ad- used before c/k; common in many English borrowings.
af-
Assimilated ad- appearing before f; visible in many everyday verbs.
ag-
Assimilation of ad- before g; shows prefix adaptation to phonology.
al-
Ad- variant before l; common in both formal and informal usage.
an-
Dual role: Greek negative “not/without” and Latin assimilated “to/toward”; meaning depends on context.
ana-
Versatile Greek prefix used across sciences and general vocabulary; meaning shifts by context.
ambi-
Latin prefix denoting two-sidedness; common in everyday and technical words.
amphi-
Greek dual-directional prefix; especially common in biology and geography.
andro-
Used in biology and tech; denotes maleness or male-related characteristics.
anthropo-
Productive in social sciences and scientific coinages about humans.
anti-
Extremely productive; forms oppositional, preventative, or counteracting compounds.
ante-
Used for temporal or positional “before”; common in legal and historical contexts.
apo-
Greek prefix denoting separation or source; common in both technical and everyday words.
arch-
Marks top rank or primacy; used in politics, religion, and compound adjectives.
archaeo-
Denotes antiquity; widespread in scientific and historical contexts.
aero-
Attaches to air- and flight-related concepts; common in engineering and everyday language.
astro-
Star- and space-related combining form; common in science and popular usage.
aster-
Root meaning “star”; appears in scientific terms and symbols.
auto-
Highly productive; denotes self-action or self-relation.
acro-
Used for extremes, heights, or outermost parts; frequent in geography and medicine.
actino-
Technical combining form in physics and biology related to rays or radiation.
acousto-
Relates to sound and hearing; used in engineering, physics, and everyday contexts.
adeno-
Medical combining form referring to glands; common in anatomy and pathology.
agrí-/agri-
Latin form relating to fields and farming; used in economics, policy, and science.
agro-
Scientific/technical combining form for agriculture and land use.
alb-
From Latin albus “white”; appears in medical, scientific, and descriptive terms.
allo-
Marks otherness or difference; widely used in biology and linguistics.
alto-
Musical and meteorological combining form meaning high; borrowed into English usages.
anaero-
Specialized biological prefix indicating absence of oxygen; common in microbiology.
anemo-
Used in meteorology and botany to denote wind-related features.
angio-
Medical and botanical combining form referring to vessels; frequent in clinical terms.
apico-
Denotes the apex or tip of a structure; used in anatomy and biology.
audio-
Common in media and technology; denotes sound or hearing.
axio-
Carries senses of axis (geometry) or value/worth (philosophy); used in technical vocabulary.
azo-
Chemical combining form important in organic chemistry and dye chemistry.
auxo-
Biology-focused form denoting growth or increase; used in microbiology and plant science.
athero-
Medical combining form referring to fatty deposits in arteries; specialized clinical use.
axo-
Neuroscience and cell-biology combining form referring to axis-like structures.
algo-
Combining form related to pain; appears in medical and psychological terms.
antho-
Botanical combining form used in biology and literary compounds.
aqua-
Common Latin combining form for water-related concepts in everyday and technical words.
atmo-
Meteorological and physical combining form relating to air or gas.
amylo-
Used in biochemistry for starch-related terms and compounds.
anthrac-
Coal- and carbon-related combining form in geology and medicine.
aleur-
Specialized botanical/chemical combining form from Greek “aleuron” (flour); limited technical use.
alkalo-
Chemistry/biology combining form for nitrogenous plant compounds; historical origin in alchemy.
azo- (duplicate avoided)
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