When you have copious amounts of loose change in your trouser pockets after being out drinking at pubs, clubs, etc.
Also, this is often a way of telling if someone has been out on the piss.
"Out at the weekend?"
"Aye, was pished. Should see the amount of f**king arse change i've got!!"

Or

Person1: "Out at the weekend?"
Person2: "Naaah, quiet one eh"
*Takes out copious amounts of change to pay for something*
Person1: "AWAY AND TALK PISH! Your pockets are hoachin' with arse change!"
by omandt April 5, 2011
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