cap
Definitions
A close-fitting head covering, typically with a visor.
A limit or restriction on the amount of money that can be spent or charged.
A protective cover or seal for an object, such as a bottle or a pen.
Examples
He wore a baseball cap to shield his eyes from the bright sun.
Please make sure to put the cap back on the bottle so the liquid doesn't spill.
The government decided to place a cap on the amount of interest banks can charge.