or Coal Sack

[ kohl-sak ]
/ ˈkoʊlˌsæk /

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