Definition of "phosphorus" []

  • 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. (noun)
  • A phosphorescent substance. (noun)
  • An allotropic nonmetallic element occurring in phosphates and living matter. Ordinary phosphorus is a toxic flammable phosphorescent white solid; the red form is less reactive and nontoxic: used in matches, pesticides, and alloys. The radioisotope phosphorus-32 (radiophosphorus), with a half-life of 14.3 days, is used in radiotherapy and as a tracer. Symbol: P; atomic no: 15; atomic wt: 30.973 762; valency: 3 or 5; relative density: 1.82 (white), 2.20 (red); melting pt: 44.1°C (white); boiling pt: 280°C (white) (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved. (c) HarperCollins Publishers Ltd 2016

Use "phosphorus" in a sentence
  • "In workers exposed to the fumes of yellow phosphorus, the bone may be so devitalised that it readily becomes infected with pyogenic organisms and undergoes a process of cario-necrosis -- the _phosphorus necrosis_ of the older writers."
  • "But is there no method of acidifying phosphorus in a slighter manner, so as to form _phosphorus_ acid?"
  • "The name phosphorus comes from the Greek word phosphoros, which means bringer of light."