/ Dictionary / Index M megalo-: Meaning and Definition of Find definitions for: megalo- Pronunciation: [key] a combining form with the meanings “large, great, grand,” “abnormally large,” used in the formation of compound words: megalopolis; megalocardia. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. megalithic astronomy megaloblast 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