Certain African returned overseas with male boxing champion (6)
I believe the answer is:
somali
'certain african' is the definition.
(I've seen this in another clue)
'returned overseas with male boxing champion' is the wordplay.
'returned' says the letters should be written backwards.
'overseas with male boxing' becomes 'mos' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'champion' becomes 'ali' (I have seen 'Champion of ring' mean 'ali' so perhaps 'champion' could also mean 'ali').
'mos' in reverse letter order is 'som'.
'som'+'ali'='SOMALI'
Can you help me to learn more?
(Other definitions for somali that I've seen before include "North-east African" , "Native of East African state" , "So Liam could be a man from NE Africa" , "From a part of northeast Africa" , "East African national" .)