Source : Webster's Revised Unabridged Dictionary (1913)

Ferrous \Fer"rous\, a. [Cf. F. ferreux. See {Ferreous}.] (Chem.)
   Pertaining to, or derived from, iron; -- especially used of
   compounds of iron in which the iron has its lower valence;
   as, ferrous sulphate.

Source : WordNet®

ferrous
     adj : of or relating to or containing iron [syn: {ferric}]