Meaning of phosphorus sesquisulfide

phos'phorus ses•qui•sul'fide

Pronunciation: (ses"kwi-sul'fīd), [key]
  1. (not in scientific use) a yellow, crystalline, flammable substance, PS, insoluble in cold water and decomposed by hot water: used chiefly in organic synthesis and in the manufacture of matches.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.