/ Dictionary / Index U upper deck: Meaning and Definition of Find definitions for: up'per deck' Pronunciation: [key] — Naut. Naut. the uppermost continuous deck that is capable of being made watertight; freeboard deck. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Upper Darby Upper Egypt Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language