To be a drinker can intoxicate (5)
I believe the answer is:
'intoxicate' is the definition.
(I've seen this in another clue)
'to be a drinker' is the wordplay.
'a drinker' becomes 'sot' (sot is a kind of drinker).
'can' is the link.
(Other definitions for besot that I've seen before include "Make stupid" , "Stupefy, make silly or foolish" , "Make love" .)