Service democratic private group (6,3)
I believe the answer is:
dinner set
'service' is the definition.
(I know that dinner set is a type of service)
'democratic private group' is the wordplay.
'democratic' becomes 'd' (political abbreviation).
'private' becomes 'inner' (as in one's private or inner thoughts).
'group' becomes 'set' (both can mean a collection).
'd'+'inner'+'set'='DINNER-SET'
(Other definitions for dinner set that I've seen before include "Plates etc" , "Complete service of plates and dishes for a meal" , "might be taken out for a meal" , "crockery" , "Collection of plates and dishes" .)