Drunk but Nellie is joyous (9)
I believe the answer is:
ebullient
'joyous' is the definition.
Both the definition and answer are adjectives. Maybe you can see an association between them that I don't see?
'drunk but nellie' is the wordplay.
'drunk' indicates an anagram.
'but'+'nellie'='butnellie'
'butnellie' is an anagram of 'EBULLIENT'.
'is' acts as a link.
Can you help me to learn more?
(Other definitions for ebullient that I've seen before include "Joyously unrestrained" , "Overflowing with enthusiasm" , "Bubbling with enthusiasm" , "Enthusiastic" , "Bubbling over with high spirits, animated" .)