/ Dictionary / Index C crackajack: Meaning and Definition of Find definitions for: crack•a•jack Pronunciation: (krak'u-jak"), [key] — n., adj. crackerjack. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. crack crackbrain Related Content Daily Word Quiz: acerbity Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language