/ Dictionary / Index S sponge rubber: Meaning and Definition of Find definitions for: sponge' rub'ber Pronunciation: [key] a light, spongy rubber, usually prepared by bubbling carbon dioxide through or whipping air into latex, used for padding, insulation, gaskets, etc.; foam rubber. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. sponger sponge tree Related Content Daily Word Quiz: spectral Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language