Red, ∨ Amorphous , phosphorus Meaning, Definition & Usage

Definitions
  1. (Chem.), an allotropic modification of phosphorus, obtained as a dark red powder by heating ordinary phosphorus in closed vessels. It is not poisonous, is not phosphorescent, and is only moderately active chemically. It is valuable as a chemical reagent, and is used in the composition of the friction surface on which safety matches are ignited.

Webster 1913