/ Dictionary / Index B ballas: Meaning and Definition of Find definitions for: bal•las Pronunciation: (bal'us), [key] — n. (used with a sing. v.) Mineral. a spherical aggregate of small diamond crystals used for drilling and for various industrial purposes. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Ballarat ballast Related Content Daily Word Quiz: pundit Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language