Fellow overlooking mine in frequent battleground (7)
I believe the answer is:
cockpit
'frequent battleground' is the definition.
(term for an area used for a battle)
'fellow overlooking mine' is the wordplay.
'fellow' becomes 'cock' (a male bird**).
'overlooking' is a charade indicator (letters next to each other) (down clues only).
'mine' becomes 'pit' (down the pit).
'cock'+'pit'='COCKPIT'
'in' acts as a link.
(Other definitions for cockpit that I've seen before include "battlefield" , "not suitable for a hen party" , "Racing driver's seat" , "Frequent battleground" , "Driver's compartment in a racing car" .)