/ Dictionary / Index M matterate: Meaning and Definition of Find definitions for: mat•ter•ate Pronunciation: (mat'u-rāt"), [key] — -at•ed, -at•ing. to fester; suppurate. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. matter Matterhorn Related Content Daily Word Quiz: cautious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language