ˈfäˌsfēn, -_sfə̇n noun
( -s )
Etymology: International Scientific Vocabulary phosph- + -ine
1. : a colorless very poisonous gaseous compound PH 3 that may ignite spontaneously when mixed with air or oxygen, that is a weaker base than ammonia but forms phosphonium salts with strong acids, and that is made in various ways (as by decomposing metallic phosphides with water)
2. : any of a class of organic compounds derived from phosphine that are analogous to amines but are much weaker bases
3. : an orange-yellow basic dye consisting essentially of a nitrate of chrysaniline — see dye table I (under Basic Orange 15 )