Main definitions of a in English

: a1A2a3A4

a1

(also an)

Pronunciation: /ə//eɪ/

determiner

  • 1Used when mentioning someone or something for the first time in a text or conversation:

    ‘a man came out of the room’
    Compare with the
    ‘it has been an honour to meet you’
    • ‘Jack crouched down and hid behind a tree trunk.’
    • ‘An internal report written by a manager at the nuclear waste reprocessing plant was leaked this week.’
    • ‘"That campaign definitely had an effect," she says.’
    • ‘Before making a decision, do an assessment of how you want to use your phone.’
    • ‘I received an email from Jo today.’
    • ‘We had to write a story about a natural disaster for creative writing.’
    • ‘Children need a place for their computer equipment, and parents need closet space for their clothing.’
    • ‘Bob's conducting a three-year internet romance with a girl he's never met.’
    • ‘My wife got me an unexpected Christmas gift this year.’
    • ‘He has also written an opera and translated Dante's Inferno in order to produce an illustrated book of it.’
    1. 1.1 Used with units of measurement to mean one such unit:
      ‘a hundred’
      ‘a quarter of an hour’
      • ‘There is barely an ounce of fat on his body, and he continues to make his team-mates look chubby.’
      • ‘The attack came amid a major upsurge in violence across the country that has left a thousand dead.’
      • ‘About a mile further down the road, another dog ran out in front of the taxi.’
      • ‘I look at these miserable people, and wouldn't trade my life with theirs for a million dollars.’
      • ‘I stopped to pick up a gallon of milk on my way home from work.’
      • ‘I sent off an e-mail, just an hour ago, and he's already got me back online.’
    2. 1.2[with negative] One single; any:
      ‘I simply haven't a thing to wear’
      • ‘I had to own up to the fact that I'd never read a word by Crofts.’
      • ‘Most refugees say they never saw a drop of food aid - despite almost one million tonnes flooding into the country every year.’
      • ‘Incensed at the fiasco, I went back to the website to try and find a telephone number to call - not a thing!’
      • ‘The film looks fantastic: there is not a spot, or a scratch, or a visual defect to be seen.’
      • ‘I think there's not a person born that doesn't have a gift to offer in some way.’
    3. 1.3 Used when mentioning the name of someone not known to the speaker:
      ‘a Mr Smith telephoned’
      • ‘He was sent two poems from a Miss Ethel Malley, who wrote saying they were found among her brother's possessions after his death.’
      • ‘She was born in about 1670, the daughter of a Mr Freeman of Holbeach in Lincolnshire.’
      • ‘The latest letter was from a Mrs Singh, who complained about two radio stations.’
      • ‘Does anyone know a Mr Daeller?’
      • ‘On September 29 a letter arrived at our address for a Ms L Doherty.’
    4. 1.4 Someone like (the name specified):
      ‘you're no better than a Hitler’
      • ‘Called a Judas by his countrymen, he received an elbow from another player, and left the pitch injured.’
      • ‘Moore says that the organization has passed its Chamberlain period, and is now in need of a Churchill.’
      • ‘What he lacks is the charisma of an Olivier, whose epochal Coriolanus is dazzlingly evoked in two pages of Kenneth Tynan's Curtains.’
      • ‘You need the methods of a Roosevelt.’
      • ‘Regarding academic medicine, it has become increasingly difficult for a Freud or a Mendel to gain recognition without university affiliation or corporate sponsorship.’
  • 2Used to indicate membership of a class of people or things:

    ‘he is a lawyer’
    ‘this car is a BMW’
    • ‘She's a banker, married to a stockbroker, and they have a daughter about the same age as Amy.’
    • ‘Notice that every car seen in the show is a Chevrolet, out of consideration for their sponsor.’
    • ‘In 1984 he was granted his fervent wish to acquire a Picasso.’
    • ‘My mom's a pharmacist and my dad's a realtor.’
    • ‘Lilly is a Siamese cat who survived a two-week cross-country move while stuck in a drawer.’
  • 3In, to, or for each; per (used when expressing rates or ratios):

    ‘typing 60 words a minute’
    ‘a move to raise petrol prices by 3p a litre’
    • ‘The site takes in 2,000 tons of trash on a typical day, charging an average $30 a ton.’
    • ‘The truckers are angry at the rise in diesel prices, which currently average 81.3p a litre.’
    • ‘The price of gold rose last week to $309 an ounce - and at one point was $312, its highest for two years.’
    • ‘You can't drive over five miles an hour down any street in New York.’
    • ‘I type 15 words a minute with a lot of mistakes.’

Usage

On the question of using a or an before words beginning with h, see an

Origin

Middle English: weak form of Old English ān ‘one’.

Pronunciation:

a

/ə//eɪ/

Main definitions of a in English

: a1A2a3A4

A2

(also a)

Pronunciation: /ə//eɪ/

noun

  • 1The first letter of the alphabet.

    1. 1.1 Denoting the first in a set of items, categories, sizes, etc.
    2. 1.2 Denoting the first of two or more hypothetical people or things:
      ‘suppose A had killed B’
    3. 1.3 The highest class of academic mark:
      ‘a dazzling array of straight A's’
    4. 1.4 (in the UK) denoting the most important category of road, other than a motorway:
      ‘the A34’
      ‘busy A-roads’
    5. 1.5 Denoting the highest-earning socio-economic category for marketing purposes, including top management and senior professional personnel.
    6. 1.6Chess Denoting the first file from the left, as viewed from White's side of the board.
    7. 1.7 The first constant to appear in an algebraic expression.
    8. 1.8Geology Denoting the uppermost soil horizon, especially the topsoil.
    9. 1.9 The human blood type (in the ABO system) containing the A antigen and lacking the B.
    10. 1.10 (with numeral) denoting a series of international standard paper sizes each twice the area of the next, as A0, A1, A2, A3, A4, etc., A4 being 210 × 297 mm.
  • 2A shape like that of a capital A:

    [in combination] ‘an A-shape’
  • 3Music
    The sixth note of the diatonic scale of C major. The A above middle C is usually used as the basis for tuning and in modern music has a standard frequency of 440 Hz.

    1. 3.1 A key based on a scale with A as its keynote.

Pronunciation:

A

/ə//eɪ/

Main definitions of a in English

: a1A2a3A4

a3

Pronunciation: /ə//eɪ/

  • 1(in travel timetables) arrives:

    ‘Penzance a 0915’
  • 2[in combination] (in units of measurement) atto- (10−18).

  • 3British (with reference to sporting fixtures) away:

    ‘March 15 Sheffield United (a)’
  • 4(used before a date) before:

    ‘a1200’

Main definitions of a in English

: a1A2a3A4

A4

Pronunciation: /ə//eɪ/

  • 1(in card games) ace:

    ‘you cash ♥AK’
  • 2Against (heading the column in a table of sports results which shows the goals or points scored against each club).

  • 3informal A level.

  • 4Ampere(s).

  • 5Ångstrom(s).

  • 6Attack (in designations of US aircraft types):

    ‘an A-10’
  • 7Answer:

    ‘Q: What is a hung parliament? A: One in which no single party has an overall majority’
  • 8(in names of sports clubs) Athletic:

    ‘Dunfermline A’
  • 9Austria (international vehicle registration).

"a"
Physics
  • Acceleration.

Pronunciation:

a

/ə//eɪ/