D defs.my
Entry 5 senses Webster, 1913

Aurora

/ẽr-ôr'-ə/ · Au·ro·ra · IPA /əˈɹɔɹ.ə/
01 n. The rising light of the morning; the dawn of day; the redness of the sky just before the sun rises.
pl. Auroras, Auroræ
  1. 1.
    The rising light of the morning; the dawn of day; the redness of the sky just before the sun rises.
  2. 2.
    The rise, dawn, or beginning.
  3. 3.
    The Roman personification of the dawn of day; the goddess of the morning. The poets represented her a rising out of the ocean, in a chariot, with rosy fingers dropping gentle dew.(Class. Myth.)
  4. 4.
    A species of crowfoot.(Bot.)
  5. 5.
    The aurora borealis or aurora australis (northern or southern lights).
Phrases & compounds
Aurora borealis — 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.
Aurora australis — is a corresponding phenomenon in the southern hemisphere, the streams of light ascending in the same manner from near the southern horizon.