Last of beer in barrel producing wind (4)
I believe the answer is:
turn
'wind' is the definition.
(thesaurus)
'last of beer in barrel' is the wordplay.
'last of' says to take the final letters.
'in' indicates putting letters inside.
'barrel' becomes 'tun' (tun is a kind of barrel).
The last letter of 'beer' is 'r'.
'r' placed within 'tun' is 'TURN'.
'producing' acts as a link.
(Other definitions for turn that I've seen before include "Sour" , "Bend, move round" , "Go; spin (cricket)" , "change for Autumn" , "Distinctive expression" .)