outsole

This term is a technical specification used primarily in footwear manufacturing and podiatry. It refers specifically to the exterior layer of the shoe, distinguishing it from the midsole, which provides cushioning, and the insole, which sits directly beneath the foot.

In a commercial or retail context, the outsole is often discussed in terms of material durability and grip, such as mentioning "Vibram outsoles" or "rubberized outsoles" to indicate high-performance traction for specific terrains.