A- or a- may refer to: ;A-hyphen * A- (plane), a U.S. military aircraft prefix *

Privative a An alpha privative or, rarely, privative a (from Latin ', from Ancient Greek ) is the prefix ''a-'' or ''an-'' (before vowels) that is used in Indo-European languages such as Sanskrit and Greek and in words borrowed therefrom to express negation or ...

, a prefix expressing negation * Copulative a, a prefix expressing unification ;A-minus * A−, a blood type in the ABO blood group system * A− (grade), an educational grade in the letter-grading system, above B+ but below A

See also