The act of winning a gold medal in a distance sport, preferably rowing, and then having sexual intercourse with the medal still on within the same night as the race.
Various levels of quinning exist as one may still quinn with the achievement of a silver or bronze medal but will dubbed as half or third quinning, respectively.
Rower 1: "Ayyy, nice job on getting first at that regatta mayne "
Rower 2: "Thanks, now I'm looking forward to quinning"
...
Rower 1: "Heard you quinned last night, hell yeah son"
Rower 2: "Yeah, but that medal got in the way a bit..."
the act of making a customer who was about to buy a car change their mind because you can not talk them into paying an extra $50-60 a month for gap insurance and an extended service contract.
"Hey David, I just finished quinning those folks because they would not buy my products and they left for another dealership"