Source : Webster's Revised Unabridged Dictionary (1913)

Javelin \Jave"lin\, v. t.
   To pierce with a javelin. [R.] --Tennyson.

Javelin \Jave"lin\, n. [F. javeline; akin to Sp. jabalina, It.
   giavelina, and F. javelot, OF. gavlot. Cf. {Gavelock}.]
   A sort of light spear, to be thrown or cast by thew hand;
   anciently, a weapon of war used by horsemen and foot
   soldiers; now used chiefly in hunting the wild boar and other
   fierce game.

         Flies the javelin swifter to its mark, Launched by the
         vigor of a Roman arm?                    --Addison.

Source : WordNet®

javelin
     n 1: an athletic competition in which a javelin is thrown as far
          as possible
     2: a spear thrown as a weapon or in competitive field events