Cogwheel and Flywheel

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

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

Flywheel noun - Regulator consisting of a heavy wheel that stores kinetic energy and smooths the operation of a reciprocating engine.

Cogwheel and flywheel are semantically related. You can use "Cogwheel" instead a noun "Flywheel".