Sword nicked young woman (7)
I believe the answer is:
cutlass
'sword' is the definition.
(type of sword)
'nicked young woman' is the wordplay.
'nicked' becomes 'cut' (nick can mean to cut).
'young woman' becomes 'lass' (informal term for a young woman).
'cut'+'lass'='CUTLASS'
(Other definitions for cutlass that I've seen before include "Sailor's blade" , "Sharp weapon" , "Old sailor's weapon" , "could hurt one, in the main" , "Sword formerly used by sailors" .)