Celtic language spoken in France (6)
I believe the answer is:
breton
'celtic language spoken in france' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for breton that I've seen before include "One from Brest" , "A native of Brittany, France" , "Frenchman" , "Cooked with cheese and/or breadcrumbs on top" , "from Northern France" .)