Aristocracy always received by servant (7)
I believe the answer is:
peerage
'aristocracy' is the definition.
(I know that peerage is a type of aristocracy)
'always received by servant' is the wordplay.
'always' becomes 'eer' (poetic way of saying ever).
'received by' indicates putting letters inside.
'servant' becomes 'page' (a royal servant).
'eer' placed within 'page' is 'PEERAGE'.
(Other definitions for peerage that I've seen before include "Aristocracy" , "Book of the nobility" , "The nobility as a group" , "Noble title and rank" , "Book listing lords and the like" .)