Coalsack definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
Astron. a prominent dark nebula in the Milky Way near the constellation Crux: usually with the
sometimes written Coal Sack
Coalsack definition by American Heritage Dictionary
- A dark nebula, one of the nearest to Earth, that appears in the southern Milky Way.
- A similar dark nebula in the Northern Hemisphere near the constellation Cygnus.