1. <chemistry> A poisonous nonmetallic element of the nitrogen group, obtained as a white, or yellowish, translucent waxy substance, having a characteristic disagreeable smell. It is very active chemically, must be preserved under water, and unites with oxygen even at ordinary temperatures, giving a faint glow, whence its name. It always occurs combined, usually in phosphates, as in the mineral apatite, in bones, etc. It is used in the composition of the tips of friction matches, and for many other purposes. The molecule contains four atoms.

Symbol: P.

Atomic weight: 31.0.

2. The morning star; Phosphor.

3. Hence, any substance which shines in the dark like phosphorus, as certain phosphorescent bodies.

Bologna phosphorus, phosphorescent substances which shine in the dark after exposure to the sunlight or other intense light.

Origin: L, the morning star, Gr, lit, light bringer; light + to bring.

(23 Jan 2009)