/ Dictionary / Index S sea level: Meaning and Definition of Find definitions for: sea' lev"el Pronunciation: [key] the horizontal plane or level corresponding to the surface of the sea at mean level between high and low tide. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. sea lettuce sea-level pressure 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