[noun] [U], [adjective] [not gradable] - (paper) of a standard size used in Europe, measuring 21 centimetres x 29.7 centimetresThe printer has run out of paper, could you get me some more A4?I must get this letter written - have you got a sheet of A4 I could use?A4 paper is twice as big as A5 and half the size of A3.Is this paper A4 or something else?
A4
Meaning of A4 in English
Cambridge English vocab. Кембриджский английский словарь. 2012