Some old capital in African country (6)
I believe the answer is:
guinea
'african country' is the definition.
(Guinea is an example)
'some old capital in' is the wordplay.
I cannot quite understand how this works, but
'some' could be 'a' and 'a' is found in the answer.
'in' is within the answer.
The remaining letters 'gue' is a valid word which might be clued in a way I don't understand.
This may be the basis of clue (or it may be nonsense).
(Other definitions for guinea that I've seen before include "one pound and five pence" , "West African republic - once worth 21 shillings" , "Former gold coin" , "Old unit of sterling worth 21 shillings" , "Gold coin - West African republic" .)