Drunk in snug (5)
I believe the answer is:
tight
This clue is a double definition.
'drunk' is the first definition.
(thesaurus)
'snug' is the second definition.
('tight' can be similar in meaning to 'snug')
'in' acts as a link.
(Other definitions for tight that I've seen before include "Close - drunk" , "Tense; secretive" , "Trim" , "Rigid; drunk" , "Drunk - a near thing!" .)