Bicycle tires are basically in three styles. Tubular which are like thin rubber hose donut that glues onto the rim, Clinchers that mount like a normal tire with a tube inside, and Tufo Tubulars that might be described as a hybrid. The high-pressure clinchers are again like a regular tire but reinforced, so unlike a bike tire from the 70's these pump up to 75psi for a low rolling resistance.
So, bicycle folks would describe tube motorcycle tires as Clinchers. It's just jargon for talking to the kid behind the bike counter on the style of tire.