One fascinating Frenchman sent up drinking song (9)
I believe the answer is:
enchanter
'one fascinating' is the definition.
(someone who fascinates or enchants)
'frenchman sent up drinking song' is the wordplay.
'frenchman' becomes 'rene' (common French name).
'sent up' shows that the letters should be reversed in order.
'drinking' means one lot of letters goes inside another.
'song' becomes 'chant' (song sung by a crowd).
'rene' in reverse letter order is 'ener'.
'ener' going around 'chant' is 'ENCHANTER'.
(Other definitions for enchanter that I've seen before include "siren, possibly" , "magician" , "One charming" .)