Having a grotesgue and disfigured head on the tip of a man's erect penis. It is caused by misuse and torture of one's cock. The bumpy helmet can cause a man to be off balance and fall over like a tethered bowling ball to your waist.
"Milton had a boner but due to his enormous bumpy helmet on the tip of his cock he lost his balance knocking Craig's reports off his desk."
by Fergloch August 25, 2010