A word most commonly used to describe a homosexual activity where three or more men stand in a circle and have anal sex all at the same time.
Derived from "Circle" only with a "faggot lisp" hence the "thirkle".
Alex looked up at John and Chris with misty eyes and said: "Wow guys, just the three of us left in the office! You know that means!"
Alex with a cheeky grin: "Thirkle..."
Chris: "I like ponies."