/ Dictionary / Index O obsolesce: Meaning and Definition of Find definitions for: ob•so•lesce Pronunciation: (ob"su-les'), [key] — -lesced, -lesc•ing. to be or become obsolescent. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: obsolesce (Thesaurus) obsolesc. obsolescence Related Content Daily Word Quiz: ontiguous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language