/ Dictionary / Index S seventy-eight: Meaning and Definition of Find definitions for: sev•enty-eight Pronunciation: (sev'un-tē-āt'), [key] — n. a cardinal number, 70 plus 8. a symbol for this number, as 78 or LXXVIII. a set of this many persons or things. —adj. amounting to 78 in number. 78 Pronunciation: (sev'un-tē-āt'), [key] — pl. 78s, 78's. an early type of shellac-based phonograph record that played at 78 revolutions per minute. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: seventy-eight (Thesaurus) seventy seventy-eighth Related Content Daily Word Quiz: procrastinate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language