Cogwheel and Cog

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

Cog and cogwheel are semantically related in toothed wheel topic. In some cases you can use "Cog" instead a noun "Cogwheel", when it comes to topics like mechanical transmission, toothed part of wheel.

Cog noun - Tooth on the rim of gear wheel.

Cogwheel and cog are semantically related in thing topic. You can use "Cogwheel" instead a noun "Cog", if it concerns topics such as toothed wheel, mechanical transmission, main part of device. popular alternative