phosphorus. The American Heritage® Dictionary of the English Language: Fourth Edition. 2000.

The American Heritage^® Dictionary of the English Language: Fourth Edition. 2000.

phosphorus

SYLLABICATION:	phos·pho·rus
PRONUNCIATION:	fsfr-s
NOUN:	1. Symbol P A highly reactive, poisonous, nonmetallic element occurring naturally in phosphates, especially apatite, and existing in three allotropic forms, white (or sometimes yellow), red, and black. An essential constituent of protoplasm, it is used in safety matches, pyrotechnics, incendiary shells, and fertilizers and to protect metal surfaces from corrosion. 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. See table at element. 2. A phosphorescent substance.
ETYMOLOGY:	Latin Phsphorus, morning star, from Greek phsphoros, bringing light, morning star : phs, light; see bh-¹ in Appendix I + -phoros, -phorous.


The American Heritage^® Dictionary of the English Language, Fourth Edition. Copyright © 2000 by Houghton Mifflin Company. Published by the Houghton Mifflin Company. All rights reserved.