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