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See also: a4 and A-4
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Etymology 1[edit]

See the Wikipedia article ISO 216, the international standard on paper sizes.


A4 (uncountable)

  1. A standard paper size, defined by ISO 216.
    dimensions: 210 x 297 mm
    • 2001, Eoin Colfer, Artemis Fowl, page 66:
      "There are preparations to be made for our guest's arrival," said Artemis, handing a typewritten sheet of A4 to Juliet.

See also[edit]

Etymology 2[edit]

Proper noun[edit]


  1. one in a series of alphanumerics used in many national road systems.
    The A4, which runs from London to Bristol, used to be known as the Great West Road.
  2. (Britain, rail transport) A4 class, a class of steam locomotive used on the London and North Eastern Railway.