/ Dictionary / Index J jack-in-the-box: Meaning and Definition of Find definitions for: jack-in-the-box Pronunciation: ( jak'in-u-boks"), [key] — pl. -box•es. a toy consisting of a box from which an enclosed figure springs up when the lid is opened. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: jack-in-the-box (Thesaurus) jacking engine jack-in-the-pulpit Related Content Daily Word Quiz: fabricate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language