Like a member of the military? (4)
I believe the answer is:
army
I believe this is a double definition.
'like a member' is the first definition.
('army' could mean like an arm)
'the military?' is the second definition.
(the armed forces)
'of' is the link.
(Other definitions for army that I've seen before include "Ground forces" , "See 6" , "Land-fighting force" , "Military unit" , "Horde" .)