seventy-eight adj 1: being eight more than seventy [syn: {seventy-eight}, {78}, {lxxviii}] n 1: the cardinal number that is the sum of seventy and eight [syn: {seventy-eight}, {78}, {LXXVIII}] 2: a shellac based phonograph record that played at 78 revolutions per minute [syn: {seventy-eight}, {78}]