/ Dictionary / Index B black guillemot: Meaning and Definition of Find definitions for: black' guil'lemot. Pronunciation: [key] See under(def. 1). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. blackguard black gum Related Content Daily Word Quiz: deleterious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language