ferreous

from The Collaborative International Dictionary of English v.0.48

Ferreous \Fer"re*ous\, a. [L. ferreus, fr. ferrum iron. Cf.
   {Farrier}, {Ferrous}.]
   Partaking of, made of, or pertaining to, iron; like iron.
   [Obs.] --Sir T. Browne.
   [1913 Webster]