Fellow with drink may cause trouble (4)
I believe the answer is:
flap
'trouble' is the definition.
(I've seen this in another clue)
'fellow with drink' is the wordplay.
'fellow' becomes 'F' (abbreviation - of a society etc.).
'with' is a charade indicator (letters next to each other).
'drink' becomes 'lap' (lap can mean to drink).
'f'+'lap'='FLAP'
'may cause' is the link.
(Other definitions for flap that I've seen before include "Move like a bird or get into a tizzy" , "State of panic" , "Tab - tizzy - move wings" , "Excitement" , "Agitated state; tab" .)