Strangely, one isn't a European (8)
I believe the answer is:
'european' is the definition.
(person from Estonia)
'strangely one isn't a' is the wordplay.
'strangely' indicates anagramming the letters.
'oneisnta' is an anagram of 'ESTONIAN'.
(Other definitions for estonian that I've seen before include "Native of a Baltic republic" , "Native of Tallinn, say" , "Balt" , "Eastern Europe" , "From Tallinn, for example" .)