Entrance curtailed for French artist (6)
I believe the answer is:
ingres
'for french artist' is the definition.
(I've seen this before)
'entrance curtailed' is the wordplay.
'entrance' becomes 'ingress' (synonyms).
'curtailed' means to remove the last letter.
'ingress' with its last letter removed is 'INGRES'.
(Other definitions for ingres that I've seen before include "French painter known for his portraits" , "Jean -; Fr. artist; singer (anag.)" , "Producer of old pictures" , "French classical painter" , "French painter of elegant portraits" .)