D defs.my
Entry 1 sense Webster, 1913

Phosphorous

/(fŏs"fŏr*ŭs)/ · Phos·phor·ous · IPA /fˈɑsfərəs/
01 a. Of or pertaining to phosphorus; resembling or containing phosphorus; specifically, designating those compounds in which phosphorus has a lo…
  1. 1.
    Of or pertaining to phosphorus; resembling or containing phosphorus; specifically, designating those compounds in which phosphorus has a lower valence as contrasted with phosphoric compounds; as, phosphorous acid, H3PO3.(Chem.)