sprockets
nounUK /ˈsprɒk.ɪts/
US /ˈsprɑː.kɪts/
Sprockets are wheels with teeth that turn a chain or belt.
The bike chain fits over the sprockets at the back wheel.
SYNONYMS
OTHER MEANINGS
2. The toothed wheels on a bicycle or motorcycle that the chain turns.
He cleaned the sprockets before oiling the chain.
3. Small toothed parts inside a machine that help it move.
The old clock's sprockets clicked softly as it ticked.
4. In film, the little holes along the edge of the film that fit onto the projector's teeth.
The projector's sprockets pulled the film smoothly through the gate.