/ Dictionary / Index U UL: Meaning and Definition of Find definitions for: UL Pronunciation: [key] Underwriters' Laboratories (used esp. on labels for electrical appliances approved by this nonprofit safety-testing organization). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. ukulele ulama Related Content Daily Word Quiz: profiterole Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language