| 1. | the first letter of the English alphabet, a vowel. |
| 2. | any spoken sound represented by the letter A or a, as in bake, hat, father, or small. |
| 3. | something having the shape of an A. |
| 4. | a written or printed representation of the letter A or a. |
| 5. | a device, as a printer's type, for reproducing the letter A or a. |
| 6. | from A to Z, from beginning to end; thoroughly; completely: He knows the Bible from A to Z. |
| 7. | not know from A to B, to know nothing; be ignorant. |
AS abbr.
Latin auris sinistra (left ear)
| A
Abbreviation of adenine, ampere, angstrom, area |
| As
The symbol for arsenic. |