Total a couple of graduates retains is capital (5,5)
I believe the answer is:
'capital' is the definition.
(capital of Ethiopia)
'total a couple of graduates retains is' is the wordplay.
'total' becomes 'add' (synonyms).
'couple of graduates' becomes 'baba' (I can't explain this - if you can you should give a lot more credence to this answer).
'retains' means one lot of letters goes inside another.
'addababa' placed around 'is' is 'ADDIS ABABA'.
Can you help me to learn more?
(Other definitions for addis ababa that I've seen before include "place in Africa" , "Hot city" , "Ethiopian capital" , "Ethiopia's capital" , "African capital" .)