/ Dictionary / Index P phosphine: Meaning and Definition of Find definitions for: phos•phine Pronunciation: (fos'fēn, -fin), [key] — n. Chem. a colorless, poisonous, ill-smelling, flammable gas, PH. any of certain organic derivatives of this compound. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: phosphine (Thesaurus) phosphide phosphite Related Content Daily Word Quiz: rustic Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language