An office game involving industrial kettles and masturbation. The aim of the game is to enter the office kitchen when no one's about and nut one out into the giant kettle, or urn, which dispenses boiling water for tasty warm beverages, without getting caught.
If you succeed, you gain the satisfaction of knowing people are supping on your jizz, and the respect of your co-workers who are also in on the game. If you fail, you are probably fired.
Jones: Why are you clearing your desk?
Gorman: I got caught urn yearning again.
Jones: I didn't. Enjoy your coffee poindexter.