/ Dictionary / Index M megacity: Meaning and Definition of Find definitions for: meg•a•cit•y Pronunciation: (meg'u-sit"ē), [key] — pl. -cit•ies. a city having a population of one million or more. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. megacephalic megacorporation Related Content Daily Word Quiz: gregarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language