Definition from Wiktionary, the free dictionary
- To assemble, or cause to be repaired or completed, an object, device, machine, or project from duct tape as the preferred repair tool, but in its absence, other items, (normally common, ordinary and mundane such as a rubber band or paper clip), not normally used for that purpose, where others would assume one needs a manufactured part, as per the design. Especially: if the items are used in ways significantly different than their intended use.
- Our car broke down and we didn't have any tools but Jim MacGyvered it with some toenail clippers and we were able to limp to the service station. 
to jury-rig — see jury-rig