• A non-metal element that has the atomic symbol P, atomic number 15, and atomic weight 31. It is an essential element that takes part in a broad variety of biochemical reactions.
  NLM Medical Subject Headings
  U.S. National Library of Medicine, 2025
• A nonmetallic element that is found in the blood, muscles, nerves, bones, and teeth and is a component of adenosine triphosphate (ATP; the primary energy source for the body's cells).
  NCI Dictionary of Cancer Terms
  U.S. National Cancer Institute, 2021
• An element with atomic symbol P, atomic number 15, and atomic weight 30.97.
  NCI
  U.S. National Cancer Institute, 2021
• Having to do with or containing the element phosphorus.
  NCI Dictionary of Cancer Terms
  U.S. National Cancer Institute, 2021
• Nonmetallic, allotropic element with atomic symbol P, atomic number 15, and atomic weight 31; an essential element in the diet, a major component of the mineral phase of bone, and abundant in all tissues; involved in some form in almost all metabolic processes.
  CRISP Thesaurus
  National Institutes of Health, 2006