Northern European (4)
'northern european' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for finn that I've seen before include "adventurer in Mark Twain story" , "Eg, Helsinki native" , "Trollope's Phineas; one from Tampere" , "EU statesman" , "Someone from Helsinki?" .)
(Other definitions for nordic that I've seen before include "Race of people in Scandinavia" , "'Of Scandinavia, Finland and Iceland (6)'" , "Relating to Germanic people of N Europe, tall and blonde" , "Relating to tall fair people of N Germany" , "Of tall, fair Germanic people" .)