1. A sack to carry coal in.
1632. Massinger, City Madam, IV. iii. (1658), 60. A Coal-sack for a winding-sheet.
1638. Ford, Fancies, I. ii. Let me be buried in a coal sack.
1854. Hull Improv. Act, 52. Penalty for using undersized coal-sacks.
2. A name given to patches in the Milky Way distinguished by extraordinary blackness, owing to the absence of even dim stars; esp. to one near the Southern Cross, formerly called also the Black Magellanic Cloud.
1870. Proctor, Other Worlds than Ours, xi. 264. In the southern Coal-sack there are minute telescopic stars.
1879. Newcomb & Holden, Astron., 415. Vacant spaces in it [Milky Way] which the navigators call coal-sacks.
