treadle

noun

1. A foot-operated pedal or lever that generates motion.

   “To the rear end of the shaft B, is attached a band wheel, to the periphery of which is attached a strap J, which descends to a treadle, to be operated by the foot, but which requires no description.”

   “There is an inconspicuous treadle let into the floor and when you step on it an air-operated door-opening mechanism is automatically activated; [...].”

2. A device actuated by wheels passing over it.

   “As a car enters the parking area the front wheels pass over a treadle, causing a timber barrier to lift and allow the motorist to drive in and park. No money is required at this stage. As the car passes over a second treadle, just beyond the entrance, the barrier falls again.”

3. Chalaza.

verb

1. (intransitive)To use a treadle.
2. (transitive)To press a specific treadle or sequence of treadles on the loom.

   “You can play with treadling a straight or point twill, treadle just Block A, treadle just Block B, or mix and match all the options.”