Hit that nail! (5)
I believe the answer is:
clout
I believe this clue is a double definition.
'hit' is the first definition.
(I've seen this before)
'that nail' is the second definition.
(clout nail is a kind of nail)
(Other definitions for clout that I've seen before include "Political influence - flat-headed nail" , "Influence; heavy blow" , "authority" , "Cast not one before May is out" , "Punch; influence" .)