/ Dictionary / Index O opsonize: Meaning and Definition of Find definitions for: op•so•nize Pronunciation: (op'su-nīz"), [key] — -nized, -niz•ing. to increase the susceptibility of (bacteria) to ingestion by phagocytes. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: opsonize (Thesaurus) opsonin -opsy Related Content Daily Word Quiz: immense Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language