/ Dictionary / Index M megabuck: Meaning and Definition of Find definitions for: meg•a•buck Pronunciation: (meg'u-buk"), [key] — n. Informal. one million dollars. very large sums of money. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. megabit megabyte 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