1. A truck. Usually a big truck, or a commercial truck with the trailer unattached. But it can refer to ANY vehicle.
This word is extrememly common in Northern Cali.
2. It can also mean to fix something haphazardly. As in Jimmy-rig.
1."The four wheel drive on my rig is broken"
"Go hop in the rig, it's time to go!"
2. "The hose was broken so we rigged it with tape."