bumcoppers 

small, pebbly, rusty-looking plops that havent been flushed and which resemble mucky old coins in a fountain.

look at how these bumcoppers have tarnished the surrounding toilet water and made it all rusty

bumcoppers by johngo August 6, 2011

bumcrumble 

like bumcheese but a few days older

Mum picked up John's pants from his bedroom floor and shook them free of BumCrumble

bumcrumble by Mark November 10, 2003

Bumcrack 

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!"

Bumcrack by BumcrackTheDog November 2, 2004

Bumcrums 

The left over particles of your most recent shit!.

Jim: Ew.. You've got bumcrums
Barry: Get the hoover, QUICK!

Bumcrums by Jerrposition February 11, 2015

East Bumcrack University 

A marginal research university that publishes man-made climate change denial research that is unsupported by mainstream institutions.

First used by Australian journalist Annabel Crabb on ABC's "Insiders" program in response to climate skeptic Andrew Bolt. Quoted in Hansard minutes of Australian Senate, Nov 2009.

That sounds like another factoid you picked from East Bumcrack University to support your climate change skeptic arguments

East Bumcrack University by Professor Toad November 19, 2009

Bumcrease 

Another word for "ass crack" usually said with a Jamaican accent.

Man 1: Oh no, I just sat in mud!
(Stands up)
Man 2(Jamaican accent): Aha! It lookes like you got shit all over your bumcrease!

Bumcrease by Luciashlo October 24, 2009

Bumcramp

When your arse cheeks tighten up and you are unable to walk properly..

Wait man i've got a bumcramp

Bumcramp by N_Gout January 16, 2010