/ Dictionary / Index T three-decker: Meaning and Definition of Find definitions for: three-deck•er Pronunciation: (thrē'dek'ur), [key] — n. any ship having three decks, tiers, etc. (formerly) one of a class of sailing warships that carried guns on three decks. a sandwich made of three slices of bread interlaid with two layers of filling; club sandwich. something having three layers, levels, or tiers. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: three-decker (Thesaurus) Three-D three-dimensional Related Content Daily Word Quiz: fresco Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language