A stupid, unintelligent, staggeringly moronic act. Derived from the name of one of the most half-witted idiots to ever infect the earth.
When Jack came home from work on a cold winter night and found that his roommate had turned the heat up to 80 degrees, then opened all the windows "because it was too hot in here," he knew he was witnessing a profound act of Gencoism.
A man who enjoys having objects inserted into his urethra. (term is derived from old-time guns that had their bullets loaded from the top of the barrel)
It was only when Mike asked Jill to insert the happy end
of a ball point pen into his penis that she realized he was a muzzleloader.