Source : Webster's Revised Unabridged Dictionary (1913)

Vanadate \Van"a*date\, n. [Cf. F. vanadate.] (Chem.)
   A salt of vanadic acid. [Formerly also {vanadiate}.]

Source : WordNet®

vanadate
     n : a salt or ester of vanadic acid; an anion containing
         pentavalent vanadium