Cogwheel and Pawl

Cogwheel noun - A toothed wheel that engages another toothed mechanism in order to change the speed or direction of transmitted motion.

Pawl and cogwheel are semantically related. In some cases you can use "Pawl" instead a noun "Cogwheel".

Pawl noun - A hinged catch that fits into a notch of a ratchet to move a wheel forward or prevent it from moving backward.

Cogwheel and pawl are semantically related. Sometimes you can use "Cogwheel" instead a noun "Pawl".