verb. The action of scraping one's fingers, hands or knuckles on a sharp edge or corner inside a computer case while removing a device such as a PCI card or drive power cable. This is usually caused by parts being difficult to remove requiring such an application of force that once the object gives the hand pulling upon it is whipped across the interior of the computer case typically resulting in multiple lascerations. A bleeding knogle occurs if the injury (injuries) result in a substantial amount of blood loss.
I knogled myself removing a Kitchen Sync dual time-base corrector from my Amiga 2000 the other day requiring the use of a bandaid. (true story!)