/ Dictionary / Index A A/O: Meaning and Definition of Find definitions for: A/O Pronunciation: [key] account of. and others. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. ANZUS AOA Related Content Daily Word Quiz: philtrum Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language