A chump is someone who gets fooled or taken advantage of easily. If you trade your rare baseball card for a sandwich, your friend might say you got played for a chump because you made a bad deal. A chump doesn't necessarily lack intelligence; they might just be too trusting or not paying attention when someone tries to trick them.

The word often appears in phrases like “don't be a chump,” meaning don't let yourself get swindled or pushed around. If a con artist sells someone a “magic rock” for twenty dollars, that person got treated like a chump. A store might try to sell cheap headphones at premium prices, hoping customers will be chumps and not check the quality.

Being called a chump stings because it suggests you were naive or gullible. Nobody wants to be the chump who falls for the oldest trick in the book. The word carries a tone of mild contempt mixed with pity, like when someone falls for an obvious prank that everyone else saw coming.