1) When someone is engaging in chump behavior, and they are checked on it by someone that knows better.
2) When someone intentionally tries to catch someone off-guard by doing something only a chump would fall for; often used in gaming circles.
1) Totally chump checked that dude on my Facebook that shared some dumb article with no sources.
2) At first I was overthinking it and trying way too hard to be tactical, but eventually I just started spamming smash attacks and chump checked his ass; turns out his defensive game is garbage.