jury leg, n. — Green’s Dictionary of Slang

jury leg n.

[ety. unknown; ? on pattern of naut. jargon jury-rigged or jury-mast, temporary rigging or a temporary mast, a short-term arrangement that replaces equipment swept away in a gale or after a battle]

a wooden leg; thus jury-legged adj.

1751		Smollett Peregrine Pickle (1964) 30: D--n ye, ye jury-legg’d dog, you would give all the stowage in your hold to be as sound as I am.
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue n.p.: Jury Leg. A wooden leg: allusion to a jury mast, which is a temporary substitute for a mast carried away by a storm, or any other accident. Sea phrase.
1811		Lex. Balatronicum [as cit. 1785].
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue [as cit. 1785].