Roman-style estate (5)
I believe the answer is:
manor
'estate' is the definition.
(I know that manor is a type of estate)
'roman-style' is the wordplay.
'style' indicates anagramming the letters (style can mean to shape or design).
'roman' anagrammed gives 'MANOR'.
(Other definitions for manor that I've seen before include "local copper's area" , "Large country house for Roman" , "patch" , "Grand but strange Roman house" , "Big house - police district" .)