A1
Pronunciation: /eɪ/
(also a)
noun ( plural As or A's)
- 1the first letter of the alphabet.
- denoting the first in a set of items, categories, sizes, etc..
- denoting the first of two or more hypothetical people or things: suppose A had killed B
- the highest class of academic mark: a dazzling array of straight A’s
- (in the UK) denoting the most important category of road, other than a motorway: the A34 busy A-roads
- denoting the highest-earning socio-economic category for marketing purposes, including top management and senior professional personnel.
- (a) Chess denoting the first file from the left, as viewed from White’s side of the board.
- (usually a) the first constant to appear in an algebraic expression.
- Geology denoting the uppermost soil horizon, especially the topsoil.
- the human blood type (in the ABO system) containing the A antigen and lacking the B.
- (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.
