[fos-fer-uh
s] 
[-fuh-rahy] . | 1. | Chemistry. a solid, nonmetallic element existing in at least three allotropic forms, one that is yellow, poisonous, flammable, and luminous in the dark, one that is red, less poisonous, and less flammable, and another that is black, insoluble in most solvents, and the least flammable. The element is used in forming smoke screens, its compounds are used in matches and phosphate fertilizers, and it is a necessary constituent of plant and animal life in bones, nerves, and embryos. Symbol: P; atomic weight: 30.974; atomic number: 15; specific gravity: (yellow) 1.82 at 20°C, (red) 2.20 at 20°C, (black) 2.25–2.69 at 20°C. |
| 2. | any phosphorescent substance. |
| 3. | phosphor. |
[fos-fer, -fawr] | the morning star, esp. Venus. |
| phos·pho·rus (fŏs'fər-əs) n.
[Latin Phōsphorus, morning star, from Greek phōsphoros, bringing light, morning star : phōs, light; see bhā-1 in Indo-European roots + -phoros, -phorous.] |
phosphorus phos·pho·rus (fŏs'fər-əs)
n.
Symbol P
A highly reactive poisonous nonmetallic element occurring naturally in phosphates, especially apatite, and an essential constituent of protoplasm. Atomic number 15; atomic weight 30.9738; melting point (white) 44.1°C; boiling point 280°C; specific gravity (white) 1.82; valence 3, 5.
A phosphorescent substance.