/ Dictionary / Index U UI: Meaning and Definition of Find definitions for: UI Pronunciation: [key] unemployment insurance. u.i. Pronunciation: [key] ut infra. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. uhuru* Uigur Related Content Daily Word Quiz: penurious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language