1 - An adjective used to describe an exaggerated feat or phenomenon.
2 - But when used as a first name, it is an incredible insult.
1 - "Man did you see that reverse belknap he pulled on his board?"
"He totally belknapped that chick, eh?"
"You just got belknapped dude"
2 - "That guy's name is Belknap... his parents must not love him"