One empty beer returned for bitter (5)
I believe the answer is:
acerb
'bitter' is the definition.
(synonyms)
'one empty beer returned' is the wordplay.
'one' becomes 'ace' (ace has a value of one in some card games).
'empty' means to remove the middle letters.
'returned' says the letters should be written backwards.
'beer' with its middle taken out is 'br'.
'br' in reverse letter order is 'rb'.
'ace'+'rb'='ACERB'
'for' is the link.
(Other definitions for acerb that I've seen before include "sharp" , "Sour, bitter" , "harsh and bitter" , "tart" .)