open to another to take. See jump, to.
1884. Rolf Boldrewood, Melbourne Memories,' c. xvi. p. 114:
«The heifer station was what would be called in miningparlance `an abandoned claim' and possibly `jumpable.'»
Jumper,
1890. Rolf Boldrewood, `Miner's Right,' c. xii. p. 127:
«Come along, my noble jumper, you've served your injunction.»