1. a wheel with teeth around the rim that fits into the links of a chain

Examples

• The bicycle chain slipped off the rear sprocket.
• Replace the worn sprocket before it damages the chain.
• The motorcycle’s sprocket needed adjustment after 10,000 miles.
• Each sprocket tooth must align perfectly with the chain links.
• The mechanic cleaned the grease from the front sprocket.
• A damaged sprocket can cause the chain to skip or break.