Fast way to get drunk (5)
I believe the answer is:
tight
I believe this clue is a double definition.
'fast' is the first definition.
(I've seen this before)
'drunk' is the second definition.
(thesaurus)
'way to get' acts as a link.
(Other definitions for tight that I've seen before include "affected by powerful liquid?" , "It's not enough" , "Taut" , "South American nation" , "Snug" .)