Army officer not specific (7)
I believe the answer is:
general
This clue is a double definition.
'army officer' is the first definition.
(type of army officer)
'not specific' is the second definition.
('general' is the opposite to 'specific')
(Other definitions for general that I've seen before include "Not specialised, rank" , "Senior military officer" , "Common - soldier" , "Regular - officer" , "High-ranking officer" .)