Coalsack
Pronunciation : Coal"sack`
Part of Speech : n.
Definition : Defn: Any one of the spaces in the Milky Way which are very black, owing to the nearly complete absence of stars; esp., the large space near the Southern Cross sometimes called the Black Magellanic Cloud.
[Coal + 2d sack.] (Astron.)
Source : Webster's Unabridged Dictionary, 1913