Guy drinks last of Sauterne (5)
I believe the answer is:
tease
'guy' is the definition.
(thesaurus)
'drinks last of sauterne' is the wordplay.
'drinks' becomes 'teas' (tea is a kind of drink).
'last of' indicates one should take the final letters.
The last letter of 'sauterne' is 'e'.
'teas'+'e'='TEASE'
(Other definitions for tease that I've seen before include "Rag" , "Torment lightly" , "Josh" , "Comb to remove tangles and open out the fibres" , "Gently make fun of (someone)" .)