Ass concrete 

The mark left on the bowl of the toilet once you've taken a huge dump

"Holy shit... Dude, clean the bowl... you left some epic ass concrete"

Ass concrete by Nigel stapleballs April 10, 2009

concrete ass 

lazy fucker who is not prepared to do any work at all

get off your seat concrete ass and get some fucking work done

concrete ass by Rgigs August 17, 2008