Property in East, say (6)
I believe the answer is:
estate
'property' is the definition.
(estate is a kind of property)
'east say' is the wordplay.
'east' becomes 'e' ('E' can be a synonym of 'east').
'say' becomes 'state' ('state' can be a synonym of 'say').
'e'+'state'='ESTATE'
'in' is the link.
(Other definitions for estate that I've seen before include "Extensive landed property (6)" , "Everything person possesses" , "Property and possessions of the deceased" , "All of one's assets -- 5-door car" , "Desmesne" .)