Constant excitement and drinking (8)
I believe the answer is:
carousal
'drinking' is the definition.
(a drunken feast)
'constant excitement' is the wordplay.
'constant' becomes 'c' (common symbol in maths for an unknown constant).
'excitement' becomes 'arousal' (I've seen this before).
'c'+'arousal'='CAROUSAL'
'and' is the link.
(Other definitions for carousal that I've seen before include "Revels" , "A drink-and-be-merry session" , "Merry drinking party" , "Drunken party" , "Lively drinking party" .)