A bad joke is joke that is so bad you don't even know how to comprehend it. It is something that was intended to be funny but when you arrive at the punchline, it leaves you confused and speechless such that the only words you can utter out of your mouth is "BAD JOKE"
Dianne: guys you want to here a joke? What's 1 + 1?
Guys: I dont know?
Dianne: 11... you get it ?
Guys: Dianne that was a Bad Joke