Jump v. t.
 1. To pass over by means of a spring or leap; to overleap; as, to jump a stream.
 2. To cause to jump; as, he jumped his horse across the ditch.
 3. To expose to danger; to risk; to hazard. [Obs.]
    To jump a body with a dangerous physic.   --Shak.
 4. Smithwork (a) To join by a butt weld. (b) To thicken or enlarge by endwise blows; to upset.
 5. Quarrying To bore with a jumper.
 To jump a claim, to enter upon and take possession of land to which another has acquired a claim by prior entry and occupation. [Western U. S. & Australia] See Claim, n., 3.
 To jump one's bail, to abscond while at liberty under bail bonds.  [Slang, U. S.]
 To jump the gun, to begin to run (in a footrace) before the starting gun has fired; hence, (fig.) to begin any activity before the designated starting time.