Source : Webster's Revised Unabridged Dictionary (1913)

Vanadium \Va*na"di*um\, n. [NL., fr. Icel. Vanad[=i]s, a surname
   of the Scandinavian goddess Freya.] (Chem.)
   A rare element of the nitrogen-phosphorus group, found
   combined, in vanadates, in certain minerals, and reduced as
   an infusible, grayish-white metallic powder. It is
   intermediate between the metals and the non-metals, having
   both basic and acid properties. Symbol V (or Vd, rarely).
   Atomic weight 51.2.

Source : WordNet®

vanadium
     n : a soft silvery white toxic metallic element used in steel
         alloys; it occurs in several complex minerals including
         carnotite and vanadinite [syn: {V}, {atomic number 23}]