Vanadious
Pronunciation : Va*na"di*ous
Part of Speech : a.
Definition : Defn: Pertaining to, or containing, vanadium; specifically, designating those compounds in which vanadium has a lower valence as contrasted with the vanadic compounds; as, vanadious acid. [Sometimes written also vanadous.]
(Chem.)
Source : Webster's Unabridged Dictionary, 1913