or Coal Sack


noun Astronomy.

a dark nebula in the southern constellation Crux, whose dust particles obscure light from Milky Way stars behind it.

Origin of Coalsack

First recorded in 1625–35; coal + sack1
Also called Southern Coalsack. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for coal sack

Coal Sack


a dark nebula in the Milky Way close to the Southern Cross
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012