Brewery wagon overturned in quadrangle (4)
I believe the answer is:
yard
'quadrangle' is the definition.
(thesaurus)
'brewery wagon overturned' is the wordplay.
'brewery wagon' becomes 'dray' (I've seen this before).
'overturned' is a reversal indicator.
'dray' in reverse letter order is 'YARD'.
'in' is the link.
(Other definitions for yard that I've seen before include "area behind the house" , "Three feet - enclosed area" , "Space outside" , "Imperial unit of length" , "Three feet out the back" .)