Heartless cook behind house wine (4)
I believe the answer is:
hock
'wine' is the definition.
(I know that hock is a type of white wine)
'heartless cook behind house' is the wordplay.
'heartless' means to remove the middle letters.
'behind' says to put letters next to each other.
'house' becomes 'ho' (abbreviation for house).
'cook' with its middle taken out is 'ck'.
'ck' after 'ho' is 'HOCK'.
(Other definitions for hock that I've seen before include "White wine and horse's joint" , "Pawn < some ham" , "A wine; part of horse's leg" , "German white wine from Rhineland" , "Rhine wine -- horse joint" .)