Crescent, one French in character, largely (7)
I believe the answer is:
lunette
'crescent' is the definition.
(I've seen this before)
'one french in character largely' is the wordplay.
I cannot really understand how this works, but
'one' could be 'un' (northern English dialect form of 'one') and 'un' is present in the answer.
'character' could be 't' and 't' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for lunette that I've seen before include "opening in dome" , "Semi-circular alcove" , "Arched aperture" , "Something crescent-shaped" , "Alcove for statue" .)