/ Dictionary / Index A antimony pentoxide: Meaning and Definition of Find definitions for: an'timony pent•ox'ide Pronunciation: (pen-tok'sīd), [key] — Chem. Chem. a white or yellowish, water-insoluble powder, SbO, used chiefly in the synthesis of antimonates. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. antimony pentasulfide antimony potassium tartrate Related Content Daily Word Quiz: labyrinth Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language