/ Dictionary / Index M megalosaur: Meaning and Definition of Find definitions for: meg•a•lo•saur Pronunciation: (meg'u-lu-sôr"), [key] — n. any gigantic carnivorous dinosaur of the genus Megalosaurus, of the Jurassic and early Cretaceous periods. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: megalosaur (Thesaurus) megalopsia -megaly Related Content Daily Word Quiz: clairvoyant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language