- Archaic any phosphorescent substance or object
- a nonmetallic chemical element, normally a white, phosphorescent, waxy solid, becoming yellow when exposed to light: it is poisonous and unites easily with oxygen, so that it ignites spontaneously at room temperature: when heated in sealed tubes it is converted into a red form, which is nonpoisonous and less flammable than the white: when heated under a pressure of 10,000 atmospheres it is converted into a black powder: symbol, P; at. no. 15: a radioactive isotope (phosphorus-32) is used in the diagnosis and treatment of certain diseases, as a tracer in chemical and biochemical research, etc.
Origin of phosphorusModern Latin from Classical Latin Phosphorus, morning star from Classical Greek ph?sphoros, bringer of light from ph?s, a light, contr. from phaos from Indo-European base an unverified form bh?-, to shine from source Classical Greek phainein, to show (from source fantasy) + -phor(o)us