Phosphorous

a.

1.

(Chem.) 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.

Adj.

1.

phosphorous - containing or characteristic of phosphorus; "phosphoric acid" Synonyms: phosphoric

atomic number 15, P, phosphoric, phosphorus