Director's call for battle (6)
I believe the answer is:
action
This clue is a double definition.
'director's call' is the first definition.
(I've seen this before)
'for battle' is the second definition.
(military action)
(Other definitions for action that I've seen before include "skirmish" , "''. . . . . . speaks louder than words'' (6)" , "Operation; engagement" , "Thing done; armed conflict" , "Film director's cry?" .)