A little-used definition of jury is intended or designated for temporary use. It’s a nautical term of unknown origin, and in its early use it usually appeared in the phrase jury mast, referring to a temporary mast put up to replace one that has been lost.1 This is the source of the verb jury-rig, meaning to assemble for temporary use, and its derivative adjective jury-rigged.
Jerry-rig is a variant spelling of jury-rig. One could call it incorrect because it entered the language several centuries after jury-rig and is obviously derived from a misspelling of the original, but it is widely used and is accepted by some dictionaries.
It would be easier to dismiss jerry-rig as incorrect if we didn’t have the separate adjective jerry-built, which means built of bad materials. Jerry-built may or may not be etymologically related to jury-rig (its origins are mysterious), but all major dictionaries agree that jerry is the correct spelling in this case.
[A]bout 45 tonnes of contaminated water had been found near a desalination unit that is part of the plant’s jury-rigged emergency cooling system. [Financial Times]
The passengers jerry-rigged the ship … by hoisting the cracked beam with a “great iron screw.” [The Salem News]
So if the Big 12 needs OU to play on Thanksgiving Weekend the week before Bedlam … it needs to jerry-rig some kind of rivalry that makes people care. [NewsOK]
The Libyan rebels displayed tremendous ingenuity in repairing, jury-rigging and improvising weapons of all kinds. [Field and Stream]