Teas brewed behind (4)
I believe the answer is:
seat
'behind' is the definition.
(synonyms)
'teas brewed' is the wordplay.
'brewed' indicates an anagram.
'teas' anagrammed gives 'SEAT'.
(Other definitions for seat that I've seen before include "MP's place in parliament" , "Take one and sit" , "Behind" , "MP's constituency" , "Somewhere to sit" .)