/ Dictionary / Index T thickness piece: Meaning and Definition of Find definitions for: thick'ness piece" Pronunciation: [key] — Theat. Theat. a narrow flat or board used in scenic construction to give the illusion of depth or solidity to a door, wall, window, or the like. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. thickness thick register Related Content Daily Word Quiz: ravenous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language