Excrete, empty one's bowels. The act of getting rid of last night's over-indulgence in curry and copious amounts of Newcastle Brown Ale. Dog's also turf out regularly, for no other reason other than to turf out in general... and pound for pound their's is bigger.
"You look relieved. Wassup?"
"Mate, I had a turf out this morning..."
"Chicken tikka chilli balti phal and 12 pints of Newky"