/ Dictionary / Index J jack chain: Meaning and Definition of Find definitions for: jack' chain" Pronunciation: [key] a chain having open links in the form of a figure 8, with one loop at right angles to the other. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. jackbooted jack cheese Related Content Daily Word Quiz: censure Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language