/ Dictionary / Index U upburst: Meaning and Definition of Find definitions for: up•burst Pronunciation: (up'bûrst"), [key] — n. a burst upward. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. upbuild UPC Related Content Daily Word Quiz: procrastinate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language