Party with little quantity of beer is in order (9)
I believe the answer is:
dominican
'order' is the definition.
(Dominican Order of monks)
'party with little quantity of beer' is the wordplay.
'party' becomes 'do' (do is a kind of party).
'with' is a charade indicator (letters next to each other).
'little' becomes 'mini'.
'quantity of beer' becomes 'can' (a can of beer).
'do'+'mini'+'can'='DOMINICAN'
'is in' is the link.
(Other definitions for dominican that I've seen before include "West Indian" , "Brother" , "Black Friar" , "Republican" , "One working in order" .)