Guy drinks noisily (5)
I believe the answer is:
tease
'guy' is the definition.
(guy can mean to tease or make fun of)
'drinks noisily' is the wordplay.
'drinks' becomes 'teas' (tea is a kind of drink).
'noisily' indicates a 'sounds like' (homophone) clue.
'teas' is a homophone of 'TEASE'.
(Other definitions for tease that I've seen before include "Chaff" , "Tantalize" , "Gently rib" , "Kid" , "Annoy good-naturedly" .)