1. a device or tool used to make something tight or tighter

Examples

• Use the belt tightener to adjust the tension on the engine belt.
• The guitar’s string tightener helps maintain proper tuning.
• He bought a new chain tightener for his bicycle.
• The fence tightener made the wire much more secure.
• This rope tightener will keep the tarp from flapping in the wind.
• The mechanic recommended replacing the old belt tightener.