/ Dictionary / Index T theorize: Meaning and Definition of Find definitions for: the•o•rize Pronunciation: (thē'u-rīz", thēr'īz), [key] — v., -rized, -riz•ing. —v.i. to form a theory or theories. —v.t. to form a theory or theories about. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: theorize (Thesaurus) theorist theory Related Content Daily Word Quiz: sylvan Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language