2. Games ace
7. or Å angstrom
10. Sports assist
a 1 or A (ā)
n. pl. a'sIdiom:
1. The first letter of the modern English alphabet.
2. Any of the speech sounds represented by the letter a.
3. The first in a series.
4. Something shaped like the letter A.
5. A The best or highest in quality or rank: grade A milk.
a. The sixth tone in the scale of C major or the first tone in the relative minor scale.
b. A key or scale in which A is the tonic.
c. A written or printed note representing this tone.
d. A string, key, or pipe tuned to the pitch of this tone.
7. A One of the four major blood groups in the ABO system. Individuals with this blood group have the A antigen on the surface of their red blood cells, and the anti-B antibody in their blood serum.
from A to Z
a 2 (ə; ā when stressed)
1. Used before nouns and noun phrases that denote a single but unspecified person or thing: a region; a person.
2. Used before terms that denote number, amount, quantity, or degree: only a few of the voters; a bit more rest; a little excited.
a. Used before a proper name to denote a type or a member of a class: the wisdom of a Socrates.
b. Used before a mass noun to indicate a single type or example: a dry wine.
4. The same: birds of a feather.
5. Any: not a drop to drink.
[Middle English, variant of an, an; see an1.]
Usage Note: In writing, the form a is used before a word beginning with a consonant sound, regardless of its spelling (a frog, a university, a euphemism). The form an is used before a word beginning with a vowel sound (an orange, an hour). · An was once a common variant before words beginning with h in which the first syllable was unstressed; thus 18th-century authors wrote either a historical or an historical but a history, not an history. This usage made sense in that people often did not pronounce the initial h in words such as historical and heroic, but by the late 19th century educated speakers usually gave their initial h's a huff, and the practice of writing an before such words began to die out. Nowadays it survives primarily before the word historical. One may also come across it in the phrases an hysterectomy or an hereditary trait. These usages are acceptable in formal writing.
a 3 (ə)
In every; to each; per: once a month; one dollar a pound.
[Middle English, from Old English an, in; see on.]
a 4 (ə)
Have: He'd a come if he could.
[Middle English, alteration of haven, to have; see have.]
2. are (measurement)
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
a (eɪ) or
, pl a's
, A's or As
1. (Linguistics) the first letter and first vowel of the modern English alphabet
2. (Phonetics & Phonology) any of several speech sounds represented by this letter, in English as in take, bag, calm, shortage, or cobra
3. (Education) Also called: alpha the first in a series, esp the highest grade or mark, as in an examination
4. from A to Z from start to finish, thoroughly and in detail
a (ə; stressed or emphatic eɪ)
(indefinite article; used before an initial consonant
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. (preceded by: once, twice, several times, etc) 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.
an informal or dialect word for have
: they'd a said if they'd known
(usually linked to the preceding noun) an informal form of of
: sorta sad
; a kinda waste
1. (General Physics) acceleration
2. (Units) are(s) (metric measure of land)
3. (Units) atto-
symbol for 1.
(Classical Music) music
a. 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
b. a key, string, or pipe producing this note
c. the major or minor key having this note as its tonic
2. (Biochemistry) a human blood type of the ABO group, containing the A antigen
3. (Automotive Engineering) (in Britain) a major arterial road: the A3 runs from London to Portsmouth.
(Film) (formerly, in Britain)
a. a film certified for viewing by anyone, but which contains material that some parents may not wish their children to see
b. (as modifier): an A film.
5. (General Physics) mass number
6. (Mathematics) the number 10 in hexadecimal notation
7. (Card Games) cards ace
8. (Chemistry) chem argon (now superseded by Ar)
9. (Electronics) ampere(s)
10. (Electrical Engineering) Also: at ampere-turn
11. (General Physics) absolute (temperature)
12. (Electronics) (in circuit diagrams) ammeter
13. (Mathematics) area
14. (General Physics) (in combination) atomic: an A-bomb; an A-plant.
15. (Chemistry) chem affinity
16. (Biochemistry) biochem adenine
a universal affirmative categorical proposition, such as all men are mortal:
often symbolized as SaP
. Compare E
a. a person whose job is in top management, or who holds a senior administrative or professional position
(Automotive Engineering) Austria (international car registration)
[from Latin a(ffirmo) I affirm]
(General Physics) angstrom unit
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
A, a (eɪ)
n., pl. A's As, a's as.
1. the first letter of the English alphabet, a vowel.
2. any spoken sound represented by this letter.
3. something shaped like an A.
4. a written or printed representation of the letter A or a. Idioms:
from A to Z, from beginning to end; completely; thoroughly: He knows the Bible from A to Z.
a1 (ə; when stressed eɪ)
1. (used before a singular noun not referring to any specific member of a class or group or referring to a member not previously mentioned): We need a new car. I spoke to a doctor.
2. any; every: A dog has four legs.
3. one: a hundred years; a dozen eggs; a yard of fabric.
4. (used indefinitely with certain quantifiers): a great many years; a few stars.
5. the same: two at a time.
6. a single portion, unit, type, or instance of: two coffees and a tea.
7. a certain; a particular: A Mr. Johnson called.
8. another; one resembling: a Cicero in eloquence.
9. a work by: a Van Gogh.
10. any; a single: not a one.
[Middle English; orig. preconsonantal phonetic variant of an1
usage: In both spoken and written English a is used before words beginning with a consonant sound (a book), an before words beginning with a vowel sound (an apple). Words that start with vowel letters but are pronounced with the consonant sound (y) or (w) are preceded by a: a union; a European; a one-room apartment. The names of the consonant letters f, h, l, m, n, r, s, and x begin with a vowel sound and thus are preceded by an: an F in geometry; to fly an SST. The names of all other consonants and of the vowel u take a: a B in Spanish; a U-turn. Words that begin with the letter h sometimes cause confusion. When the h is not pronounced, the word is preceded by an: an hour. When h is pronounced, the word is preceded by a: a history of the Sioux; a hero sandwich. (Formerly, an was used before pronounced h:an hundred.) Usage is divided, however, with such words as historian, historical, heroic, and habitual, which begin with an unstressed syllable in which h may be weak or silent. The use of a is widespread in both speech and writing (a historian of ancient China; a habitual criminal), but an is also common. Hotel and unique are occasionally preceded by an, but this use is regarded as old-fashioned.
a2 (ə; when stressed eɪ)
for or in each; for or in every; per: ten cents a ride; three times a day.
[orig. Middle English a,
preconsonantal variant of on
); confused with a1
Pron. Spelling. of (often written as part of a single word, without a hyphen): the time a day; kinda; sorta.
Pron. Spelling. have (often written as part of a single, unhyphenated word): We shoulda gone.
1. the first in order or in a series.
2. (sometimes l.c.) (in some grading systems) a grade or mark indicating excellence or superiority.
a. the sixth tone of the ascending C major scale.
b. the tonality having A as the tonic.
7. (formerly) argon.
8. mass number.
are (unit of measurement).
atomic (used in combination): A-bomb; A-plant.
a reduced form of the Old English preposition on, meaning “on,” “in,” “into,” “to,” “toward,” preserved before a noun or adjective in a prepositional phrase, forming a predicate adjective or an adverbial element (afar; afoot; aloud; ashore; away). By analogy with original nominal collocations, a-1 has been joined to verbs, the resulting formation having the force of a present participle (ablaze; astride; awash).
[Middle English, late Old English; compare a2
a reduced form of the Old English preposition of: akin; afresh.
a verbal prefix with the historical sense “out, up,” occurring in verbs and verb derivatives inherited from Old and Middle English, usu. marking the inception or completion of the action denoted by the base verb: abide; accursed; arise; ashamed; awake.
[Middle English; Old English]
var. of ab
- before b, m,
and v: amanuensis; avert.
[Middle English < Latin ā-, a-]
var. of ad-
, used before sc, sp, st
) and in words of French derivation, often with the sense of increase or addition (amass
[Middle English, in some words < Middle French a-
< Latin ad-
prefix or ad
preposition (see ad
-), as in abut
; in others < Latin a-
(variant of ad- ad
-), as in ascend
var. of an-1
before a consonant: amoral; atonal; achromatic.
a plural ending of nouns borrowed from Greek and Latin: phenomena; criteria; data.
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; pachysandra.
a suffix occurring in the names of oxides of the chemical element denoted by the stem: alumina; thoria.
[< Latin annō, abl. of annus]
[< Latin ante]
[< Latin ante]
11. are (unit of measurement).
12. Baseball. assist; assists.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
1. 'a' and 'an'
You usually use a and an when it is not clear or important which specific thing or person you are referring to. You only use a and an with singular countable nouns. When you are talking about a specific person or thing, you usually use the.
She decided to buy a car.
He parked the car in front of the bakery.
You can describe someone or something using a or an with an adjective and a noun, or with a noun followed by more information.
His brother was a sensitive child.
The information was contained in an article on biology.
Don't omit a or an in front of a noun when the noun refers to someone's profession or job. For example, you say 'He is an architect'. Don't say 'He is architect'.
She became a lawyer.
2. 'a' or 'an'?
You use a in front of words beginning with consonant sounds and an in front of words beginning with vowel sounds.
Then I saw a tall woman standing by the window.
We live in an old house.
You use an in front of words beginning with 'h' when the 'h' is not pronounced. For example, you say 'an honest man'. Don't say 'a honest man'.
The meeting lasted an hour.
An is used in front of the following words beginning with 'h':
You use a in front of words beginning with 'u' when the 'u' is pronounced /juː/ (like 'you'). For example, you say 'a unique occasion'. Don't say 'an unique occasion'.
He was a university professor.
She became a union member.
A is used in front of the following words:
You use an in front of an abbreviation when the letters are pronounced separately and the first letter begins with a vowel sound.
Before she became an MP, she was a social worker.
He drives an SUV.
3. 'a' meaning 'one'
A and an are used to mean 'one' in front of some numbers and units of measurement.
Collins COBUILD English Usage © HarperCollins Publishers 1992, 2004, 2011, 2012