noun, often attributive \ˈfäs-f(ə-)rəs\

chemistry : a poisonous chemical element that glows in the dark and burns when it is touched by air

Full Definition of PHOSPHORUS

:  a phosphorescent substance or body; especially :  one that shines or glows in the dark
also phos·pho·rous \same\ :  a nonmetallic element of the nitrogen family that occurs widely especially as phosphates — see element table


New Latin, from Greek phōsphoros light-bearing — more at phosphor
First Known Use: 1645


noun , often attrib \ˈfäs-f(ə-)rəs\   (Medical Dictionary)

Medical Definition of PHOSPHORUS

: a nonmetallic multivalent element that occurs widely in combined form especially as inorganic phosphates in minerals, soils, natural waters, bones, and teeth and as organic phosphates in all living cells and that exists in several allotropic forms—symbol P; see element table


noun    (Concise Encyclopedia)

Nonmetallic chemical element, chemical symbol P, atomic number 15. The ordinary allotrope, called white phosphorus, is a poisonous, colourless, semitransparent, soft, waxy solid that glows in the dark (see phosphorescence) and combusts spontaneously in air, producing dense white fumes of the oxide PO; it is used as a rodenticide and a military smokescreen. Heat or sunlight converts it to the red phosphorus allotrope, a violet-red powder that does not phosphoresce or ignite spontaneously. Much less reactive and soluble than white phosphorus, it is used in manufacturing other phosphorus compounds and in semiconductors, fertilizers, safety matches, and fireworks. Black phosphorus, made by heating the white form under pressure, is flaky like graphite. Phosphorus seldom occurs uncombined in nature. As the phosphate ion, it is abundant and widely distributed, in apatite, phosphorite, and many other minerals. Phosphorus has valence 3 or 5 in compounds, which have many uses in industry. Phosphine (PH) is a chemical raw material and a doping agent (deliberately added impurity) for solid-state electronics components. Organic phosphorus compounds are used as plasticizers, gasoline additives, insecticides (e.g., parathion), and nerve gases. In living organisms the role of phosphorus is essential; it is a component of DNA and RNA, ATP, and bone.


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