Lively party in joint associated with drink (5-2)
I believe the answer is:
knees-up
'lively party' is the definition.
(I've seen this before)
'joint associated with drink' is the subsidiary indication.
'joint' becomes 'knee' (knee is a kind of joint).
'associated with' says to put letters next to each other.
'drink' becomes 'sup' (I've seen this before**).
'knee'+'sup'='kneesup'
'in' is the link.
(Other definitions for knees-up that I've seen before include "Lively informal party" , "Dance with Mother Brown" , "Riotous dance - party" , "Lively party (colloq.)" , "Informal party with dancing" .)