a

¹ American  

[uh, ey] / ə, eɪ /

indefinite article

1. not any particular or certain one of a class or group.

   a man; a chemical; a house.

2. a certain; a particular.

   one at a time; two of a kind; A Miss Johnson called.

3. another; one typically resembling.

   a Cicero in eloquence; a Jonah.

4. one (used before plural nouns that are preceded by a quantifier singular in form): a hundred men (comparehundreds of men ); a dozen times (comparedozens of times ).

5. indefinitely or nonspecifically (used with adjectives expressing number).

   a great many years; a few stars.

6. one (used before a noun expressing quantity).

   a yard of ribbon; a score of times.

7. any; a single.

   not a one.

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a ² American  

[uh, ey] / ə, eɪ /

preposition

1. each; every; per.

   ten cents a sheet; three times a day.

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a ³ American  

[uh] / ə /

preposition

1. Informal. a reduced, unstressed form of of (often written as part of a single, unhyphenated word).

   cloth a gold; time a day; kinda; sorta.

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a ⁴ American  

[uh] / ə /

auxiliary verb

Informal.

1. a reduced, unstressed form of auxiliary have following some modals, as might, should, could, would, and must (usually written as part of a single, unhyphenated word).

   We shoulda gone.

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a ⁵ American  

[uh, a, ah] / ə, æ, ɑ /

pronoun

British Dialect.

1. he.

2. she.

3. it.

4. they.

5. I.

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a ⁶ American  

abbreviation

Measurements.

1. are; ares.

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A ⁷ American  

[ey] / eɪ /

Or a

noun

plural

A's, As, a's, as

1. the first letter of the English alphabet, a vowel.

2. any spoken sound represented by the letter A or a, as in bake, hat, father, or small.

3. something having the shape of an A .

4. a written or printed representation of the letter A or a.

5. a device, as a printer's type, for reproducing the letter A or a.

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idioms

1. not know from A to B, to know nothing; be ignorant.

2. from A to Z, from beginning to end; thoroughly; completely.

   He knows the Bible from A to Z.

A ⁸ American  

abbreviation

1. Electricity. ampere; amperes.

2. Physics. angstrom; angstroms.

3. answer.

4. British. arterial (used with a road number to designate a major highway).

   Take the A525 to Ruthin.

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A ⁹ American  

Symbol.

1. the first in order or in a series.

2. Sometimes a

   1. (in some grading systems) a grade or mark, as in school or college, indicating the quality of a student's work as excellent or superior.

   2. (in some school systems) a symbol designating the first semester of a school year.

3. Music.

   1. the sixth tone in the scale of C major or the first tone in the relative minor scale, A minor.

   2. a string, key, or pipe tuned to this tone.

   3. a written or printed note representing this tone.

   4. (in the fixed system of solmization) the sixth tone of the scale of C major, called la.

   5. the tonality having A as the tonic note.

4. Physiology. a major blood group, usually enabling a person whose blood is of this type to donate blood to persons of group A or AB and to receive blood from persons of O or A.

5. Sometimes a the medieval Roman numeral for 50 or 500.

6. Chemistry. (formerly) argon.

7. Chemistry, Physics. mass number.

8. Biochemistry.

   1. adenine.

   2. alanine

9. Logic. Also a universal affirmative.

10. British. a designation for a motion picture recommended as suitable for adults.

11. a proportional shoe width size, narrower than B and wider than AA.

12. a proportional brassiere cup size, smaller than B and larger than AA.

13. a quality rating for a corporate or municipal bond, lower than AA and higher than BBB.

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Å ¹⁰ American  

Symbol, Physics.

1. angstrom.

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a' ¹¹ American  

[ah, aw] / ɑ, ɔ /

Or a

adjective

Scots

1. all.

   for a' that.

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a- ¹² American  

1. a reduced form of the Old English preposition on, meaning “on,” “in,” “into,” “to,” “toward,” preserved before a noun in a prepositional phrase, forming a predicate adjective or an adverbial element (afoot; abed; ashore; aside; away ), or before an adjective (afar; aloud; alow ), as a moribund prefix with a verb (acknowledge ), and in archaic and dialectal use before a present participle in -ing (set the bells aringing ); and added to a verb stem with the force of a present participle (ablaze; agape; aglow; astride; and originally,awry ).

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a- ¹³ American  

1. a reduced form of the Old English preposition of: akin; afresh; anew.

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a- ¹⁴ American  

1. an old point-action prefix, not referring to an act as a whole, but only to the beginning or end: She arose (rose up). They abided by their beliefs (remained faithful to the end).

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a- ¹⁵ American  

1. variant of ab- before p and v: aperient; avert.

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a- ¹⁶ American  

1. variant of ad-, used: (1) before sc, sp, st (ascend ) and (2) in words of French derivation (often with the sense of increase, addition).

   amass.

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a- ¹⁷ American  

1. variant of an- before a consonant, meaning “not,” “without”.

   amoral; atonal; achromatic.

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-a ¹⁸ American  

1. a plural ending of nouns borrowed from Greek and Latin.

   phenomena; criteria; data; errata; genera.

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-a ¹⁹ American  

1. a feminine singular ending of nouns borrowed from Latin and Greek, also used in New Latin coinages to Latinize bases of any origin, and as a Latin substitute for the feminine ending - ē of Greek words: cinchona;

   anabaena;

   cinchona;

   pachysandra.

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-a ²⁰ American  

1. an ending of personal names forming feminines from masculines.

   Georgia; Roberta.

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-a ²¹ American  

1. a suffix designating the oxide of the chemical element denoted by the stem.

   alumina; ceria; thoria.

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A- ²² American  

1. atomic (used in combination).

   A-bomb; A-plant.

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a. ²³ American  

abbreviation

1. year.

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a. ²⁴ American  

abbreviation

1. before.

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a. ²⁵ American  

abbreviation

1. about.

2. acre; acres.

3. active.

4. adjective.

5. alto.

6. ampere; amperes.

7. anonymous.

8. answer.

9. are; ares.

10. Baseball. assist; assists.

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A. ²⁶ American  

abbreviation

1. year.

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A. ²⁷ American  

abbreviation

1. before.

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A. ²⁸ American  

abbreviation

1. Absolute.

2. Academy.

3. acre; acres.

4. America.

5. American.

6. angstrom.

7. answer.

8. April.

9. Artillery.

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A ¹ British  

symbol

1. music

   1. a note having a frequency of 440 hertz ( A above middle C ) or this value multiplied or divided by any power of 2; the sixth note of the scale of C major

   2. a key, string, or pipe producing this note

   3. the major or minor key having this note as its tonic

2. a human blood type of the ABO group, containing the A antigen

3. (in Britain) a major arterial road

   the A3 runs from London to Portsmouth

4. 1. a film certified for viewing by anyone, but which contains material that some parents may not wish their children to see

   2. ( as modifier )

      an A film

5. mass number

6. the number 10 in hexadecimal notation

7. cards ace

8. chem argon (now superseded by Ar )

9. ampere(s)

10. Also: at.  ampere-turn

11. absolute (temperature)

12. (in circuit diagrams) ammeter

13. area

14. (in combination) atomic

    an A-bomb

    an A-plant

15. chem affinity

16. biochem adenine

17. logic a universal affirmative categorical proposition, such as all men are mortal: often symbolized as SaP Compare E I 2 O 1

18. 1. a person whose job is in top management, or who holds a senior administrative or professional position

    2. ( as modifier ) See also occupation groupings

       an A worker

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abbreviation

1. Austria (international car registration)

a ² British  

/ ə, eɪ /

determiner

1. used preceding a singular countable noun, if the noun is not previously specified or known

   a dog

   a terrible disappointment

2. used preceding a proper noun to indicate that a person or thing has some of the qualities of the one named

   a Romeo

   a Shylock

3. used preceding a noun or determiner of quantity

   a cupful

   a dozen eggs

   a great many

   to read a lot

4. used preceding a noun indicating a concrete or abstract thing capable of being divided

   half a loaf

   a quarter of a minute

5. each or every; per

   once a day

   fifty pence a pound

6. a certain; one

   to change policy at a stroke

   a Mr Jones called

7. (preceded by not) any at all

   not a hope

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a ³ British  

symbol

1. acceleration

2. are(s) (metric measure of land)

3. atto-

4. chess See algebraic notation

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a ⁴ British  

/ eɪ /

noun

1. the first letter and first vowel of the modern English alphabet

2. any of several speech sounds represented by this letter, in English as in take, bag, calm, shortage, or cobra

3. Also called: alpha.  the first in a series, esp the highest grade or mark, as in an examination

4. from start to finish, thoroughly and in detail

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A. ⁵ British  

abbreviation

1. acre(s) or acreage

2. America(n)

3. answer

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a- ⁶ British  

prefix

1. on; in; towards

   afoot

   abed

   aground

   aback

2. literary (used before a present participle) in the act or process of

   come a-running

   go a-hunting

3. in the condition or state of

   afloat

   alive

   asleep

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Å ⁷ British  

symbol

1. angstrom unit

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a- ⁸ British  

prefix

1. not; without; opposite to

   atonal

   asocial

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a ⁹ British  

/ ə /

verb

1. an informal or dialect word for have

   they'd a said if they'd known

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a ¹⁰ British  

/ ə /

preposition

1. (usually linked to the preceding noun) an informal form of of

   sorta sad

   a kinda waste

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a' ¹¹ British  

/ ɔː /

determiner

1. variants of all

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A ¹ Scientific  

1. Abbreviation of adenine, ampere, angstrom, area

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Å ² Scientific  

1. Abbreviation of angstrom

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a– ³ Scientific  

1. A prefix meaning “without” or “not” when forming an adjective (such as amorphous, without form, or atypical, not typical), and “absence of” when forming a noun (such as arrhythmia, absence of rhythm). Before a vowel or h it becomes an– (as in anhydrous, anoxia).

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Grammar

In both spoken and written English the choice of a1 or an ¹ is determined by the initial sound of the word that follows. Before a consonant sound, a is used; before a vowel sound, an : a book, a rose; an apple, an opera. Problems arise occasionally when the following word begins with a vowel letter but actually starts with a consonant sound, or vice versa. Some words beginning with the vowel letter u and all words beginning with the vowel letters eu are pronounced with a beginning consonant sound, as if the first letter were y : a union; a European. Some other spellings that begin with a vowel letter may also stand for an initial consonant sound: a ewe; a ewer. The words one and once and all compounds of which they are the first element begin with a w sound: a one-room apartment; a once-famous actor. The names of the consonant letters f, h, l, m, n, r, s, and x are pronounced with a beginning vowel sound. When these letters are used as words or to form words, they are preceded by an : to rent an L-shaped studio; to fly an SST. The names of the vowel letter u and the semivowel letters w and y are pronounced with a beginning consonant sound. When used as words, they are preceded by a : a U-turn; The plumber installed a Y in the line. In some words beginning with the letter h, the h is not pronounced; the words actually begin with a vowel sound: an hour; an honor. When the h is strongly pronounced, as in a stressed syllable at the beginning of a word, it is preceded by a : a history of the Sioux; a hero sandwich. (In former times an was used before strongly pronounced h in a stressed first syllable: an hundred. ) Such adjectives as historic, historical, heroic, and habitual, which begin with an unstressed syllable and often with a silent or weakly pronounced h, are commonly preceded by an, especially in British English. But the use of a rather than an is widespread in both speech and writing: a historical novel; a habitual criminal. Hotel and unique are occasionally preceded by an, but this use is increasingly old-fashioned. Although in some dialects an has yielded to a in all cases, edited writing reflects usage as described above.

Etymology

Origin of a¹

First recorded in 1200–50; Middle English; originally preconsonantal phonetic variant of an ¹

Origin of a²

Originally Middle English a, preconsonantal variant of on ( a- ¹ ); confused with a ¹

Origin of a³

Middle English; unstressed preconsonantal variant of of ¹

Origin of a⁴

First recorded in 1300–50; Middle English; a phonetic variant of have

Origin of a⁵

First recorded in 1200–50; Middle English a, ha

Origin of a-¹²

Middle English, late Old English; a ², nowadays

Origin of a-¹³

Middle English; a ³

Origin of a-¹⁴

Middle English; Old English a- (unstressed), ǣ-, ā-, ō- (stressed; abb, woof ¹, oakum ), rarely or- ( ordeal ), ultimately from unattested Germanic uz- from unstressed Indo-European uss-, from ud-s (these latter two also unattested), akin to out; in some cases confused with a- ⁴, as in abridge

Origin of a-¹⁵

Middle English < Latin ā-, a- (variant of ab- ab- ); in some words < French a- < Latin ab-, as in abridge

Origin of a-¹⁶

Middle English, in some words < Middle French a- < Latin ad- prefix or ad preposition ( ad- ), as in abut; in others < Latin a- (variant of ad- ad- ), as in ascend

Origin of -a²⁰

From Latin feminine ending -a, as Claudia, feminine of Claudius; -a ²

Origin of -a²¹

Probably generalized from the -a of magnesia

Origin of a.²³

< Latin annō, ablative of annus

Origin of a.²⁴

From the Latin word ante

Origin of A.²⁶

< Latin annō, ablative of annus

Origin of A.²⁷

From the Latin word ante

Example Sentences

“He’s a winner. Everywhere he goes and every place he stops, he wins,” Green said.

From Los Angeles Times • Apr. 8, 2026

In a statement shared with US media partner CBS News on Wednesday, Brian Hooker said he was "heartbroken" about his wife's disappearance and thanked authorities and volunteers for the ongoing search.

From BBC • Apr. 8, 2026

Corona 3, Arcadia 2: Anthony Murphy finished with two hits and Trey Ebel had a triple for the Panthers.

From Los Angeles Times • Apr. 8, 2026

Michael Cooper’s return to Cal State Los Angeles is more than just another coaching stop — it’s a homecoming.

From Los Angeles Times • Apr. 8, 2026

“We’ll find her,” she promises while flipping a silver switch beside the wheel.

From "Legendary Frybread Drive-In" by Cynthia Leitich Smith

Related Words

• an