Breadcrumb Home > Dictionary > Index K knuckle ball: Meaning and Definition of Find definitions for: knuck'le ball" Pronunciation: (nuk'lur). [key] — Baseball. Baseball. a slow pitch that moves erratically toward home plate, usually delivered by holding the ball between the thumb and the knuckles of the first joints of the first two or three fingers. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: knuckleball (Thesaurus) knuckle knuckleballer TrendingHere are the facts and trivia that people are buzzing about. Did Birds Evolve from Dinosaurs? The Twelve Dancing Princesses Current Events This Week: January 2023 African Americans by the Numbers Andersen's Fairy Tales: Contents The Celtic Twilight: A Teller of Tales ✖ Related Content Daily Word Quiz: limpid Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language