1. Pure, unadulterated stupidity. Daftness of a magnitude that shocks beyond words. Total and complete lack of reason. Utter futile uselessness. Such wanton disregard for logic as to render silent all within earshot of the event.
From the English "bum" (see ass) and "fuck"
1. I won't stand for this bumfuckery, by Jove. I'm going home.