Rural Dictionary

A

–noun,pluralA's or As, a's or as.

A Nasdaq stock symbol specifying that the stocks are Class "A" shares of the company.

OR

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.
—Idioms
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.

OR

–indefinite article
1.
not any particular or certain one of a class or group: a man; a chemical; a house.
2.
a certain; a particular: one at a time; two of a kind; A Miss Johnson called.
3.
another; one typically resembling: a Cicero in eloquence; a Jonah.
4.
one (used before plural nouns that are preceded by a quantifier singular in form): a hundred men (compare hundreds of men); a dozen times (compare dozens of times).
5.
indefinitely or nonspecifically (used with adjectives expressing number): a great many years; a few stars.
6.
one (used before a noun expressing quantity): a yard of ribbon; a score of times.
7.
any; a single: not a one.

Also:

Origin:
ME; orig. preconsonantal phonetic var. of an1