/ Dictionary / Index C coal ball: Meaning and Definition of Find definitions for: coal' ball" Pronunciation: [key] a spherical mass of mineral and plant material embedded in coal beds, ranging in size from that of a pea to that of a boulder. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. coala coalbin Related Content Daily Word Quiz: dissonant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language