| 1. colorful display of natural lights that can sometimes be seen at nighttime in northern regions, northern lights. aurora borealis the aurora of the northern hemisphere [syn: northern lights]aurora borealis , i. e., northern daybreak; popularly called northern lights. a luminous meteoric phenomenon, visible only at night, and supposed to be of electrical origin. this species of light usually appears in streams, ascending toward the zenith from a dusky line or bank, a few degrees above the northern horizon; when reaching south beyond the zenith, it forms what is called the corona, about a spot in the heavens toward which the dipping needle points. occasionally the aurora appears as an arch of light across the heavens from east to west. sometimes it assumes a wavy appearance, and the streams of light are then called merry dancers. they assume a variety of colors, from a pale red or yellow to a deep red or blood color. the..see: aurora |