Hamlet's fencing opponent (7)
I believe the answer is:
laertes
'hamlet's fencing opponent' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for laertes that I've seen before include "Someone opposed to Prince" , "... killer of prince" , "Hamlet's killer" , "character in Hamlet" , "Brother of Ophelia (Hamlet)" .)