Meaning of A in English

A

/ eɪ; NAmE / noun , symbol , abbreviation

■ noun (also a ) ( pl. As , A's , a's / eɪz; NAmE /)

1.

[ C , U ] the first letter of the English alphabet :

'Apple' begins with (an) A / 'A'.

2.

A [ C , U ] ( music ) the 6th note in the scale of C major

3.

[ C , U ] the highest mark / grade that a student can get for a piece of work or course of study :

She got (an) A in / for Biology.

He had straight A's (= nothing but A's) all through high school.

4.

A [ U ] used to represent the first of two or more possibilities :

Shall we go for plan A or plan B?

5.

A [ U ] used to represent a person, for example in an imagined situation or to hide their identity :

Assume A knows B is guilty.

—see also A-frame , A level , A-road

IDIOMS

- from A to B

- from A to Z

■ symbol

1.

used in Britain before a number to refer to a particular important road :

the A34 to Newbury

2.

used (but not in the US) before numbers which show standard metric sizes of paper :

a sheet of A4 paper (= 297×210mm)

A3 (= 420×297mm)

A5 (= 210×148mm)

■ abbreviation

(in writing) amp(s)

Oxford Advanced Learner's English Dictionary.      Оксфордский английский словарь для изучающик язык на продвинутом уровне.