Pole in a fight (4)
I believe the answer is:
spar
I believe this is a double definition.
'pole' is the first definition.
(I know that spar is a type of pole)
'a fight' is the second definition.
(I know that spar is a kind of fight)
'in' acts as a link.
(Other definitions for spar that I've seen before include "bar" , "Mineral; plane's wing beam" , "Raps with large timber" , "Crystalline mineral" , "Sticks" .)