/ Dictionary / Index S siloxane: Meaning and Definition of Find definitions for: si•lox•ane Pronunciation: (si-lok'sān), [key] — n. Chem. any of the class of compounds containing the structural unit RSiO, where R is an organic group or hydrogen. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: siloxane (Thesaurus) Silone silt Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language