Soldier with battle-axe catching head of opponent (7)
I believe the answer is:
dragoon
'soldier' is the definition.
(dragoon is a kind of soldier)
'battle-axe catching head of opponent' is the wordplay.
'battle-axe' becomes 'dragon' (I've seen this before).
'catching' is an insertion indicator.
'head of' says to take the initial letters.
The initial letter of 'opponent' is 'o'.
'dragon' going around 'o' is 'DRAGOON'.
'with' is the link.
(Other definitions for dragoon that I've seen before include "Cavalry soldier" , "Shanghai" , "Cavalier" , "bring into line" , "[CARIBINEER]?" .)