Useful American-only colloquial expressions

Even though English is spoken all around the world and quite a few countries use it as their main language, it does not mean that those countries can fully understand each other. Besides the differences in accents and some minor spelling varieties, there are also expressions which are exclusively used in some parts of the world.
When you go to the United States, there are few appropriable slang words and phrases worth to know.
There is some of them:

• a buck - while paying for something, do not be surprised to pay in bucks = dollars
• to pass the buck - in this case it does not mean money, but to put the blame on someone
• a creep - when you hear that you are a creep, it means that you are weird
• to give a ring - don't take off your ring, just call someone
• to lighten up - to chill and relax!
• hyped - if something is hyped = superexciting
• pants - in the USA it means trousers (however it means the underwear for the Brits!)
• to take a raincheck - to postpone (originally to postpone a baseball match)
• to put up your dukes - better get ready for a fight
• Jonesing - when jonesing for something, you are reeeeaaaallllyyy craving for something
• John Hancock - if you hear "Let me have your John Hancock" you should not think of anything obscene - the person is just asking for your signature

Task: Try to find a few more tricky expressions and use them in the next conversation. Check the reaction of the interlocutor!