/ Dictionary / Index S sea lettuce: Meaning and Definition of Find definitions for: sea' let"tuce Pronunciation: [key] any seaweed of the genus Ulva, having large leaflike blades. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. sealery sea level Related Content Daily Word Quiz: winsome Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language