The Collaborative International Dictionary
Vanadic
Vanadic \Va*nad"ic\, a. (Chem.) Pertaining to, or obtained from, vanadium; containing vanadium; specifically distinguished those compounds in which vanadium has a relatively higher valence as contrasted with the vanadious compounds; as, vanadic oxide.
Vanadic acid (Chem.), an acid analogous to phosphoric acid, not known in the free state but forming a well-known series of salts.
Wiktionary
vanadic
a. Of or pertaining to vanadium, especially to vanadium with an oxidation number of 5.