What is Tread ?
Tread is (noun) 1. the top part of a stair or step which you stand on The carpet on the bottom tread is loose. Metal treads are noisy. 2. a pattern of lines cut into the surface of a tyre You need to change your tyres the tread’s worn. 3. a way of walking He walked up to the door with a firm tread. (verb) to step or to walk She trod on my toe and didn’t say she was sorry. Watch where you’re treading there’s broken glass on the floor. to tread on someone’s toes to offend someone to tread water to move your legs in water as if walking, so as to keep upright
source: Easier English, Student Dictionary Upper Intermediate Level