Source : Webster's Revised Unabridged Dictionary (1913)

Phosphine \Phos"phine\, n. (Chem.)
   A colorless gas, {PH3}, analogous to ammonia, and having a
   disagreeable odor resembling that of garlic. Called also
   {hydrogen phosphide}, and formerly, {phosphureted hydrogen}.

   Note: It is the most important compound of phosphorus and
         hydrogen, and is produced by the action of caustic
         potash on phosphorus. It is spontaneously inflammable,
         owing to impurities, and in burning produces peculiar
         vortical rings of smoke.

Source : WordNet®

phosphine
     n : a colorless gas with a strong fishy smell; used as a
         pesticide