Something that's jury-rigged is makeshift or thrown together from available parts. Kids love jury-rigged forts, made of blankets and chairs, even though they're not fancy.
After a fender bender, you might keep your bumper from dragging on the ground with a jury-rigged solution involving duct tape and a bungee cord. Your brother's jury-rigged skateboard ramp might be less successful. Jury-rigged was originally a nautical term — a jury-rig was a backup mast that sailors would bring on long voyages in case the original mast was damaged. Using the word jury to mean "temporary" or "makeshift" might be rooted in the Latin adjutare, "to aid or help."