/ Dictionary / Index K knuckleballer: Meaning and Definition of Find definitions for: knuck•le•ball•er Pronunciation: (nuk'ul-bô"lur), [key] — n. Baseball. a pitcher who specializes in throwing knuckle balls. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. knuckle ball knucklebone Related Content Daily Word Quiz: panacea Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language