/ Dictionary / Index L locking piece: Meaning and Definition of Find definitions for: lock'ing piece" Pronunciation: [key] — Horol. Horol. (in a striking train) a hooked part, rising and falling on a locking plate and arresting the rotation of the plate after the proper number of strokes. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. lock-in locking plate Related Content Daily Word Quiz: arboreal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language