חפשו מילה כלשהי, כמו bye felicia:
 
1.
To un-intentionally show you bum. Usually only the top part is revealed when bending down. Or if you’re a builder of some description you will already be wearing loosely fitting pants that assist in revealing your bum crack.
I was walking along the street when I saw two moons looking at me. The fattest builder was showing every one his bum crack. To which I shouted out say no to crack!
מאת Harpo 20 ביולי, 2004
 
2.
An inch long crevice found on the derriere, that has escaped the modest covering from trousers.
"Cor, look at her bumcrack, the dirty slapper! You could park a car in that!"
מאת BumcrackTheDog 2 בנובמבר, 2004
 
3.
Completely pointless person, thing or action. Something that offers no value for its existence.
Your goatee is a bumcrack.

That bumcrack professor barely teaches us anything in class.
מאת Food fiends 5 בדצמבר, 2010