A word that describes a statement that is both believable yet ridiculous. The statement is such that, if one is told that it is ridiculous and false, they would readily agree so. However, if they were told it was true, they would have their doubts but go along with it.
Alison: Hey... did you hear about that astronaut who rode across the country in a diaper to confront the "other woman"??
Sonali: Wow, really??
Alison: Yea, go google it.
Sonali: after googling wow, that's nuts.
Alison: Haha, j/k. That's ridiculous... only a completely insane person would do that. Can you imagine??
Sonali: Yea, haha, you're right. No one would ever do that, not in a million years...
Alison's original statement is totally believabulous.