Any man or woman who is so inept in the kitchen that they chew on frozen pizza bruv. if they've had too much to drink and need to throw up, they will proceed to take down their trousers revealing their crack, thus the name. You know when a jack the crack is elated as they say "decent". A JC loves to fight for their own entertainment and youll know when they are up for it by them yelling "cooooome on". They are especially horny for larger woman and look for a "bad B with a big back". A Jack the Cracks street slang comes from their desperation to escape their loving white middle class family. All in all a decent geezer.

When you think up something brilliantly righteous while baked.