Skip to definition.
Get the FREE one-click dictionary software for Windows or the iPhone/iPad and Android apps

Noun: selenium  si'lee-nee-um
  1. A toxic nonmetallic element related to sulphur and tellurium; occurs in several allotropic forms; a stable grey metallike allotrope conducts electricity better in the light than in the dark and is used in photocells; occurs in sulphide ores (as pyrite)
    - Se, atomic number 34

Derived forms: seleniums

Type of: antioxidant, chemical element, element

Part of: fool's gold, iron pyrite, pyrite

Encyclopedia: Selenium