Ferrous (Fe2+), in chemistry, indicates a divalent iron compound (+2 oxidation state), as opposed to ferric, which indicates a trivalent iron compound (+3 oxidation state).[1]
Outside of chemistry, 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 (with a carbon content of a few percent) 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]