Have the nerve (4)
I believe the answer is:
dare
'have the nerve' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for dare that I've seen before include "Challenge to do something foolhardy" , "Dan - - , 'Eagle' pilot" , "Be bold enough (to)" , "Venture, have courage" , "Challenge of courage" .)