Origin: Germanic Old English prefix
Outsole has 2 different meanings across 1 category:
the outer sole of a shoe or boot that is the bottom of the shoe and makes contact with the ground
"I need to replace my running shoes because the outsole has worn down completely from all the miles I've logged."
The underside of a shoe, which makes contact with the floor.
"I noticed a sharp rock had cut through the rubber outsole and was now digging into my foot while I walked on the trail."