Old coin found by North African (7)
I believe the answer is:
guinean
'african' is the definition.
(Guinean is an example)
'old coin found by north' is the wordplay.
'old coin' becomes 'guinea' (historical type of coin).
'found by' means one lot of letters go next to another.
'north' becomes 'N' (abbreviation).
'guinea'+'n'='GUINEAN'
(Other definitions for guinean that I've seen before include "sanguine answering guards" , "African" .)