/ Dictionary / Index B ballium: Meaning and Definition of Find definitions for: bal•li•um Pronunciation: (bal'ē-um), [key] — n. bailey. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. ballistospore ball joint Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language