Apache leader (8)
I believe the answer is:
geronimo
'apache leader' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for geronimo that I've seen before include "battle cry" , "Apache chieftain - US paratroopers war cry when jumping" , "[APACHE] leader" , "One 15 [PLAYING] 24 33 [AT SIXES AND SEVENS]" , "American shout on jumping out of an aeroplane?" .)