Symbols:A

Hexadecimal

 * $\mathrm A$ or $\mathrm a$

The hexadecimal digit $10$.

Alternating Group

 * $A_n$

The alternating group on $n$ letters.

Inverse

 * a-

Prefix indicating anti.

An abbreviation for arc, anti- or argument.

Also see

 * Definition:Arctangent
 * Definition:Antilogarithm

Linguistic

 * a-

Prefix indicating not.

Also see

 * Definition:Asymmetric Relation