/ Dictionary / Index M Mesozoic: Meaning and Definition of Find definitions for: Mes•o•zo•ic Pronunciation: (mez"u-zō'ik, mes"-, mē"zu-, -su-), [key] — Geol. Geol. —adj. noting or pertaining to an era occurring between 230 and 65 million years ago, characterized by the appearance of flowering plants and by the appearance and extinction of dinosaurs. See table under —n. the Mesozoic Era or group of systems. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: mesozoic (Thesaurus) mesozoan mesquite Related Content Daily Word Quiz: vertigo Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language