[1] : WordNet (r) 2.0

jump on
     v : get on the back of; "mount a horse" syn: hop on, mount,
          mount up, get on, climb on, bestride ant: hop
         out
see also:
hop on mount mount up get on climb on bestride 
hop out 

[2] : Moby Thesaurus II by Grady Ward, 1.0

49 moby thesaurus words for "jump on":
   asphyxiate, bottle up, call down, censor, choke off, clamp down on,
   come down on, cork, cork up, crack down on, crush, damp down,
   dress down, drown, extinguish, gag, give it to, hold down,
   jump all over, keep down, keep under, kill, muzzle, pour water on,
   put down, quash, quell, quench, repress, shut down on, silence,
   sit down on, sit on, smash, smother, speak to, squash, squelch,
   stanch, stifle, strangle, stultify, subdue, suffocate, suppress,
   talk to, tell off, throttle, trim

Jump >> J Words
Jump, definition of term: Jump
jump_pag1.html

Jump Shot >> J Words
Jump Shot, definition of term: Jump Shot
jump+shot_pag1.html

Jump Out >> J Words
Jump Out, definition of term: Jump Out
jump+out_pag1.html

Jump Rope >> J Words
Jump Rope, definition of term: Jump Rope
jump+rope_pag1.html