Meaning of AN in English

AN

I. a S1 W1 /ə; strong eɪ/ BrE AmE ( also an ) indefinite article , determiner

1 . used to show that you are talking about someone or something that has not been mentioned before, or that your listener does not know about:

We have a problem.

There was a hole in the fence.

Suddenly they heard a loud bang.

⇨ ↑ the 1

2 . used to show that you are referring to a general type of person or thing and not a specific person or thing:

Would you like a sandwich?

I want to train to be an engineer.

He’s a really nice man.

Take a look at this.

It needs a good clean.

3 . used before someone’s family name to show that they belong to that family:

One of his daughters had married a Rothschild.

4 . one:

a thousand pounds

a dozen eggs

You’ll have to wait an hour or two.

5 . used in some phrases that say how much of something there is:

There were a lot of people at the party.

A few weeks from now I’ll be in Venice.

You have caused a great deal of trouble.

6 . used to mean ‘each’ when stating prices, rates, or speeds:

I get paid once a month.

The eggs cost $2 a dozen.

7 . used before singular nouns to mean all things of a particular type:

A square has four sides (=all squares have four sides) .

A child needs love and affection.

8 . used once before two nouns that are mentioned together very often:

I’ll fetch you a cup and saucer.

Does everyone have a knife and fork?

9 . used before the -ing forms of verbs when they are used as nouns referring to an action, event, or sound:

There was a beating of wings overhead.

Bernice became aware of a humming that seemed to come from all around her.

10 . used before nouns that are usually ↑ uncountable when other information about the quality, feeling etc is added by an adjective, phrase, or ↑ clause :

Candidates must have a good knowledge of chemistry.

11 . used before the name of a substance, food etc to refer to a particular type of it:

Use a good cheese to make the sauce.

plants that grow well in a moist soil

12 . used before the name of a drink to refer to a cup or glass of that drink:

Can I get you a coffee?

Renwick went to the bar and ordered a beer.

13 . used before the name of a famous artist to refer to a painting by that artist:

an early Rembrandt

14 . used before a name to mean someone or something that has the same qualities as that person or thing:

She was hailed as a new Marilyn Monroe.

15 . used before someone’s name when you do not know who they are:

There is a Mr Tom Wilkins on the phone.

16 . used before the names of days, months, seasons, and events in the year to refer to a particular one:

We arrived in England on a cold wet Sunday in 1963.

I can’t remember a Christmas like it.

• • •

GRAMMAR

a, an

Before a word beginning with a vowel sound, use an :

an elephant

an umbrella

an obvious mistake

► Use an before an 'h' that is not pronounced:

an hour later

an honest explanation

► Use a before a 'u' that is pronounced like 'you':

a university

a unique opportunity

► Use an before an abbreviation that is pronounced with a vowel sound at the start:

an SOS call

an MP3 file

II. an S1 W1 /ən; strong æn/ BrE AmE indefinite article , determiner

used when the following word begins with a vowel sound ⇨ a :

an orange

an X-ray

Longman Dictionary of Contemporary English.      Longman - Словарь современного английского языка.