Being foreign, he’s not exactly a Briton (6)
I believe the answer is:
breton
'being foreign he's not exactly a briton' is the definition.
Although both the answer and definition are singular nouns, I don't understand how they can define each other.
'being foreign he's not' is the wordplay.
I cannot quite understand how this works, but
'being' could be 'b' (B is an example) and 'b' is present in the answer.
an anagram of 'not' is 'ton' which is present in the answer.
The remaining letters 're' is a valid word which might be clued in a way I don't see.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for breton that I've seen before include "Inhabitant of NW France" , "Cooked with cheese and/or breadcrumbs on top" , "Surrealist" , "French Celtic language" , "One from Brest" .)