claim-jumping

(historical, Australia, Western US) To enter upon and take possession of land to which another has acquired a claim by prior entry and occupation.

(Australia) To take part in a competition where riders attempt to stay on a horse that jumps in this way.

(AU) The action (of a horse) of aggressively attempting to buck a rider.

(Australia) Of a horse, to jump upwards with arched back and head down in an attempt to throw its rider.

(US) To skip to the head of a queue without waiting for one's turn.