/ Dictionary / Index I IAT: Meaning and Definition of Find definitions for: IAT Pronunciation: [key] international atomic time. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. -iasis IATA Related Content Daily Word Quiz: rustic Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language