Monk sounds drunk on gin (8)
I believe the answer is:
trappist
'monk' is the definition.
(member of the Trappist order of monks)
'sounds drunk on gin' is the wordplay.
'sounds' shows a homophone (sound like).
'drunk' becomes 'pissed' (slang term).
'on' is a charade indicator (letters next to each other).
'gin' becomes 'trap' (I've seen this before).
'pissed' is a homophone of 'pist'.
'pist' put after 'trap' is 'TRAPPIST'.
(Other definitions for trappist that I've seen before include "Holy man of very few words!" , "who likes to be silent?" , "Member of an order of monks noted for austerity and silence" , "One of an austere and silent order" , "Past trip (anag.)" .)