A legal right as a foreigner (5)
I believe the answer is:
alien
'a foreigner' is the definition.
('alien' can be a synonym of 'foreigner')
'a legal right' is the wordplay.
'legal right' becomes 'lien' (type of property right).
'a'+'lien'='ALIEN'
'as' is the link.
(Other definitions for alien that I've seen before include "extraneous" , "ET" , "Martian, say" , "of foreigners" , "Someone from outer space?" .)