Grapple, tussle (7)
I believe the answer is:
wrestle
I believe this clue is a double definition.
'grapple' is the first definition.
(I know that grapple can be written as wrestle)
'tussle' is the second definition.
(I've seen this before)
(Other definitions for wrestle that I've seen before include "Fight - get to grips (with)" , "Fight in the ring" , "Fight; struggle" , "Grapple on canvas" , "Grapple; strive" .)