/ Dictionary / Index M merci beaucoup*: Meaning and Definition of Find definitions for: mer•ci beau•coup Pronunciation: (mer-sē' bō-k'), [key] — French. French. thank you very much. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Mercian Mercier Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language