African capital beginning to advance military outfits (5)
I believe the answer is:
units
'outfits' is the definition.
The answer and definition can be both man-made objects as well as being plural nouns.
Perhaps you can see an association between them that I can't see?
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for units that I've seen before include "Single things" , "Figure on the right" , "Shops in a mall, for example" , "Individual things or groups" , "Apparatus similar to barbecue" .)