To put a limit or restriction on something. The government decided to cap the number of visas issued each year.
To cover the top or end of something. She capped the bottle to prevent the liquid from spilling.
To surpass or outdo something. He capped his performance with a stunning finale.
To complete or finish something in a notable way. The team capped their season with a championship win.
To select (an athlete) for a national team, or for the athlete to make such an appearance. He was capped ten times by his country.
Slang. To shoot or kill (someone) with a gun. The gangster threatened to cap anyone who crossed him.