Breadcrumb Home > Dictionary > Index O obsolescence: Meaning and Definition of Find definitions for: ob•so•les•cence Pronunciation: (ob"su-les'uns), [key] — n. the state, process, or condition of being or becoming obsolete. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: obsolescence (Thesaurus) obsolesce obsolescent ✖ Related Content Daily Word Quiz: spectral Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language