The first letter of the English alphabet, called a and written in the Latin script.

A rank, normally the highest rank, on any of various scales that assign letters. / (education) The highest letter grade assigned (disregarding plusses and minuses).

Ace. (including in card games) / Acre. / Adult; as used in film rating. / Ammeter. / (physics) Angstrom. / Answer. / (sports) An assist. / (sexuality) Asexual. / (UK, London) Arsehole. / (weaponry) Atom.

The ordinal number first, derived from this letter of the English alphabet, called a and written in the Latin script.

(weaponry) Atom; atomic.

Alternative form of A1

Alternative form of y- (archaic and dialectal) In dialect, it is sometimes conflated with sense 5 of the previous definition, and is used as a general indicator of a participle.

(no longer productive) Of, from.

(no longer productive) Away from.

Not, without, opposite of.