The adjective ferruginous may mean: Containing iron, applied to water, oil, and other non-metals Having rust on the surface With the rust (color) See also Ferrous, containing iron (for metals and alloys) or iron(II) cations Ferric, containing iron(III) cations Ferrate, anions containing iron Ferruginous body, a nodule indicative of asbestos inhalation Ferruginea (disambiguation) List of birds described as ferruginous