/ Dictionary / Index C cos lettuce: Meaning and Definition of Find definitions for: cos' let'tuce Pronunciation: [key] romaine. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. cosine law cosm- Related Content Daily Word Quiz: agitated Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language