/ Dictionary / Index S seat belt: Meaning and Definition of Find definitions for: seat' belt" Pronunciation: [key] a belt or strap in an automobile, airplane, etc., fastened around or sometimes diagonally across the midsection to keep the person safely secured, as during a sudden stop. Also calledCf. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: seatbelt (Thesaurus) sea tangle seater Related Content Daily Word Quiz: inutiae Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language