Slack arse
Does not mean an unfirm bottom, but it means a person who is very lazy
I had to fire David as he was a slack arse
Slack arse
A word used for someone who receives anal a lot.
That girl Wendy over there, I heard the whole football team has put it up her arse. She must be a right slack arse.
slack-arsed
Term used to describe someone who is known for dropping an inordinate number of farts, usually to their to own delight.
Eh, you shit?
Yeah! (gleefully)
You slack-arsed bastard!
Yeah! (gleefully)
You slack-arsed bastard!