A haphazard creation, made from unconventional parts or methods. A way of making something work, although it may be missing key parts.
"I only had a cardboard box and a box of adult diapers, but I managed to rig up quite a comfortable sleeping arrangement!"
"You know, from a distance, the carnival rides looked safe but, upon closer inspection, I noticed that they were rigged up with duct tape!"
To erect, build, or create something through unconventional means, often through improvisation based on a lack of funds, a key ingredient, or know-how.
Mary Sue, not having the same resources as all of the other girls in the Strawberry Queen contest, had rigged up a dress made of threadbare curtains decorated with her bedazzler.