To make an incredibly inept attempt at something with little or no forethought or experience.
I always thought, when I was a child, that one day I would wake up and miraculously have all of life's answers, but as I have gotten older I realize how badly my parents fumblefucked their way through life!
Adj. Verb. Noun. To, or the process of, being copulated or sodomized by Dumbledore. To be dumblefucked is to be sexually intimate with an elderly wizard who is a gentle lover. Grammatically flexible as in Fuck. Not to be confused with Dumbfuck.
Orign, English.
Ophelia: I am going to Dumblefuck you Tawny. Tawny: Shut up, you dumblefuck. Lance: DUMBLEFUCK! I just stubbed my toe.
Loveless: You are such a Dumblefuck.