外人 gaijin, “outsider”
gaikokujin (外国人), meaning “foreigner”.
外 soto outside
国 kuni country
人 hito person
Another word that was once used was
kōmōjin (紅毛人, literally “red-haired people”)
Haha. That could not be used here as the red haired, blond haired and black/brown haired are all natives.
I wouldnt used non-gael here either as the gaels or celts are relatively new historically.