Large piece of land in European country (6)
I believe the answer is:
estate
'large piece of land' is the definition.
(I've seen this before)
'european country' is the wordplay.
'european' becomes 'E' (abbreviation e.g. EU).
'country' becomes 'state' (synonyms).
'e'+'state'='ESTATE'
'in' acts as a link.
(Other definitions for estate that I've seen before include "Piece of land with a large house or many small ones" , "Tea-set (anag.)" , "Housing area" , "Area of landed property" , "Possessions at the time of death" .)