Breadcrumb Home > Dictionary > Index S slap-up: Meaning and Definition of Find definitions for: slap-up Pronunciation: (slap'up"), [key] — adj. Brit. Informal. excellent; first-rate: a slap-up do. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: slap-up (Thesaurus) slapstick slash ✖ Related Content Daily Word Quiz: rocrustean Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language