Verses with the word barbarians in the New Testament (2 verses):

Acts 28:4
And when the barbarians saw the venomous beast hang on his hand, they said among themselves, No doubt this man is a murderer, whom, though he hath escaped the sea, yet vengeance suffereth not to live.

Romans 1:14
I am debtor both to the Greeks, and to the Barbarians; both to the wise, and to the unwise.