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 ...

, a prefix expressing negation *

Copulative a Copulative may refer to: * Copula (linguistics), a part of speech * Copulation (zoology) In zoology, copulation is animal sexual behavior in which a male introduces sperm into the female's body, especially directly into her reproductive tra ...

, a prefix expressing unification ;A-minus * A−, a

blood type A blood type (also known as a blood group) is based on the presence and absence of antibody, antibodies and Heredity, inherited antigenic substances on the surface of red blood cells (RBCs). These antigens may be proteins, carbohydrates, glycop ...

* A− (grade), an educational grade in the letter-grading system, above B+ but below A

See also