A scrimper is someone who saves as much money as they can and spends as little as possible.
Being a scrimper can be seen as a good thing because it means you are careful with your money, but it can also be seen as a bad thing because it means you don't like to spend money.
Examples:
My mom is a scrimper and she never buys new things.
He's such a scrimper, he never goes out to eat.
The scrimper saved all his money in a big jar.
The scrimper wouldn't even buy a new shirt when his old one got holes in it.
The scrimper never spends any money, not even on candy!
The scrimper is always looking for ways to save money.