Ferrous, in the chemical science realm, indicates a bivalent iron compound (+2 oxidation state) (as opposed to ferric, which indicates a trivalent iron compound (+3 oxidation state)).[1]
Outside of chemical science, ferrous is an adjective used to indicate the presence of iron.[1] The word is derived from the Latin word ferrum (iron).[2] Ferrous metals include steel and pig iron (which contain a few percent of carbon) and alloys of iron with other metals (such as stainless steel.)
The term non-ferrous is used to indicate metals other than iron and alloys that do not contain an appreciable amount of iron.[3]
