Common soldier (7)
I believe the answer is:
general
This clue is a double definition.
'common' is the first definition.
(I know that common can be written as general)
'soldier' is the second definition.
(I know that general is a type of military officer)
(Other definitions for general that I've seen before include "Common - army officer" , "position" , "The senior officer is common and widespread" , "Not particular or specific" , "Non-specialist - army officer" .)