Contrary to popular belief, “jury rigging” has nothing to do with rigging a jury, or at least as we know it. Wikipedia to the rescue!

Jury rigging refers to makeshift repairs or temporary contrivances, made with only the tools and materials that happen to be on hand. Originally a nautical term, on sailing ships a jury rig is a replacement mast and yards improvised in case of damage or loss of the original mast.

Also of note: the phrase I originally googled, “jerry-rigging,” has nothing to do with rigging a guy named Jerry. It is actually a bastardization of jury rigging and jerry-built. The latter means that something’s a piece of crap, and it’s Jerry’s fault.