Leave from French region (6)
I believe the answer is:
depart
'leave' is the definition.
('depart' can be a synonym of 'leave')
'from french region' is the wordplay.
'from french' becomes 'de' (French for 'from').
'region' becomes 'part' ('part' can be a synonym of 'region'**).
'de'+'part'='DEPART'
(Other definitions for depart that I've seen before include "Take one's leave, go" , "Make an exit" , "Set out" , "make tracks" , "Petard (anag.)" .)