One that might have a hand in a bungled action (4)
I believe the answer is:
muff
'bungled action' is the definition.
(term for a blunder or poorly executed action)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for muff that I've seen before include "Hand-warmer - from Donegal?" , "something to keep her hands warm" , "miss" , "Hand warmer - bungle" , "where hands may need a warm-up" .)