/ Dictionary / Index C Coalsack: Meaning and Definition of Find definitions for: Coal•sack Pronunciation: (kōl'sak"), [key] — n. Astron. a dark nebula in the southern constellation Crux, whose dust particles obscure light from Milky Way stars behind it. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. coal pit coal scuttle Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language