The French entrance an emissary (6)
I believe the answer is:
legate
'an emissary' is the definition.
(legate is a kind of emissary)
'the french entrance' is the wordplay.
'the french' becomes 'le'.
'entrance' becomes 'gate' (I've seen this before).
'le'+'gate'='LEGATE'
(Other definitions for legate that I've seen before include "Vatican emissary" , "papal emissary" , "Papal ambassador" , "Emissary representing the Pope" , "Envoy - pope's representative" .)