German dialect slang for possibly a bent or rusty nail; something useless. Usually used as a name for a child who is trying to be helpful but is not succeeding. See stupenägel. Possibly arachaic. Does not refer to a thing or applied to an adult.
Ach, du bist 'n stupenaegel. Translation: You're a stoopnagle. (You are useless!).
by Otto2 December 16, 2013