vanadous

Of or pertaining to vanadium: as, vanadous oxid: specifically noting compounds in which vanadium has a lower valence than in the vanadic compounds.

Of or pertaining to vanadium; obtained from vanadium; — said of an acid containing one equivalent of vanadium and two of oxygen; specifically, designating those compounds in which vanadium has a lower valence as contrasted with the vanadic compounds

Of, pertaining to or containing vanadium, especially in an oxidation number of 4.