/ Dictionary / Index S spillproof: Meaning and Definition of Find definitions for: spill•proof Pronunciation: (spil'prf"), [key] — adj. (of a container) designed to prevent spilling. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. spillover spillway Related Content Daily Word Quiz: paradox Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language