Reason for being in France (6,5)
I believe the answer is:
raison detre
'reason' is the definition.
The definition and answer can be both related to thinking as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'being in france' is the wordplay.
I cannot really see how this works, but
'in france' could be 'et' (I've seen this in other clues) and 'et' is found within the answer.
'being' could be 'dr' (Dr is an example) and 'dr' is found in the leftover letters.
This may be the basis of the clue (or it may be nonsense).
'for' is the link.
Can you help me to learn more?
(Other definitions for raison detre that I've seen before include "existing motive?" , "Why one is" , "Reason for existence (6,1'4)" , "Justification for existence" , "Reason for living" .)