/ Dictionary / Index I irruption: Meaning and Definition of Find definitions for: ir•rup•tion Pronunciation: (i-rup'shun), [key] — n. a breaking or bursting in; a violent incursion or invasion. a sudden increase in an animal population. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: irruption (Thesaurus) irrupt irruptive Related Content Daily Word Quiz: spectral Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language