/ Dictionary / Index L lock washer: Meaning and Definition of Find definitions for: lock' wash"er Pronunciation: [key] a washer placed under a nut on a bolt or screw, so made as to prevent the nut from shaking loose. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. lockup Lockwood Related Content Daily Word Quiz: tactful Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language