Source : Webster's Revised Unabridged Dictionary (1913)

Titanium \Ti*ta"ni*um\, n. [NL., fr. L. Titani or Titanes, Gr.
   ?, the sons of the earth.] (Chem.)
   An elementary substance found combined in the minerals
   manaccanite, rutile, sphene, etc., and isolated as an
   infusible iron-gray amorphous powder, having a metallic
   luster. It burns when heated in the air. Symbol Ti. Atomic
   weight 48.1.

Source : WordNet®

titanium
     n : a light strong gray lustrous corrosion-resistant metallic
         element used in strong light-weight alloys (as for
         airplane parts); the main sources are rutile and ilmenite
         [syn: {Ti}, {atomic number 22}]