/ Dictionary / Index C crossjack: Meaning and Definition of Find definitions for: cross•jack Pronunciation: (krôs'jak", kros'-Naut.krô'jik, kroj'ik), [key] — n. Naut. the lowermost square sail set on the mizzenmast of a ship or of a bark with four or more masts; mizzen course. See diag. under Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: crossjack (Thesaurus) crossing over cross-legged Related Content Daily Word Quiz: digression Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language