Coal"sack` (?), n. [Coal + 2d sack.] (Astron.) 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"sack` (?), n. [Coal + 2d sack.] (Astron.) 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.