or Coal Sack
[ kohl-sak ]
/ ˈkoʊlˌsæk /
a dark nebula in the southern constellation Crux, whose dust particles obscure light from Milky Way stars behind it.
Also called Southern Coalsack.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for 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