Why are northern lights called aurora borealis?

Answer 1

Aurora sort of translates to "lights" (it's the name of the Greek goddess of the dawn). Boreas was the Greek god of north winds. So Borealis means "northern". So it translates almost directly to "northern lights". BTW, Aurora Borealis is technically the proper term for them.

Answer 2

The term "aurora borealis" comes from the Roman goddess of dawn, Aurora, and the Greek name for the north wind, Boreas. The phenomenon was named by Galileo Galilei in the 17th century after he observed it in the northern latitudes.