Return a first-class beer in royal possession (7)
I believe the answer is:
regalia
'royal possession' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'return a first-class beer' is the wordplay.
'return' says the letters should be written backwards.
'a first class' becomes 'ai' (A1 - top quality).
'beer' becomes 'lager' (lager is a kind of beer).
'ai'+'lager'='ailager'
'ailager' written backwards gives 'REGALIA'.
'in' is the link.
Can you help me to learn more?
(Other definitions for regalia that I've seen before include "Emblems of royalty used at coronations" , "Royal insignia" , "Trappings of royalty" , "Paraphernalia indicative of high office" , "Badges of office" .)