ˈfäsf(ə)rəs noun
( plural phospho·ri -sfəˌrī, -ˌrē)
Etymology: New Latin, from Greek phōsphoros light-bearing, from phōs- phos- + -phoros -phorous
1. : a phosphorescent substance or body ; especially : one that shines or glows in the dark
2. : a nonmetallic multivalent element of the nitrogen family that occurs widely in combined form especially as inorganic phosphates in minerals (as the apatites), soils, natural waters, bones, and teeth and as organic phosphates in all living cells and that exists in several allotropic forms including (1) a low-melting distillable corrosive poisonous white or yellowish soft waxy crystallizable solid which glows faintly in air and ignites readily in warm moist air giving off dense white smoke, which is manufactured usually from phosphate rock, sand, and coke in an electric furnace, and which is used chiefly in making phosphorus pentoxide, phosphoric acid, phosphates, and other phosphorus compounds, in incendiaries and screening smokes, and in roach and rat poisons, (2) a violet to red nonpoisonous less reactive powder obtained by heating white phosphorus with a catalyst (as iodine) at temperatures usually around 250° C and used chiefly in the abrasive surfaces on which safety matches are to be scratched and in pyrotechnics, and (3) a black electrically conducting solid resembling graphite and obtained by heating white phosphorus to high temperatures under high pressure — symbol P ; see element table