Breadcrumb Home > Dictionary > Index U U bolt: Meaning and Definition of Find definitions for: U bolt Pronunciation: [key] a bar of iron bent into the shape of afitted with a screw thread and nut at each end. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. U-boat U.C. ✖ Related Content Daily Word Quiz: quadrumanous Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language