rubber processed so that it has a spongelike texture that is firmer and denser than foam rubber: used for gaskets, rubber balls, etc.
sponge rubber in American English
noun
a light, spongy rubber, usually prepared by bubbling carbon dioxide through or whipping air into latex, used for padding, insulation, gaskets, etc.; foam rubber
Word origin
[1885–90]This word is first recorded in the period 1885–90. Other words that entered Englishat around the same time include: booster, retread, seminar, upsweep, zoom