Hacienda in Spain, say (6)
I believe the answer is:
estate
'hacienda' is the definition.
(thesaurus)
'spain say' is the wordplay.
'spain' becomes 'e' (abbreviation for Espana).
'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 "The whole of one's worldly goods" , "Lands" , "Sort of car" , "Rank - housing development - what's left in a will" , "A group of buildings built together in one development" .)