First class drinks party (9)
I believe the answer is:
reception
I believe this is a double definition.
'first class' is the first definition.
(I've seen this before)
'drinks party' is the second definition.
(I've seen this before)
(Other definitions for reception that I've seen before include "Welcome" , "class of youngsters" , "First class" , "Entrance for office" , "drinks party" .)