/ Dictionary / Index D dead-air space: Meaning and Definition of Find definitions for: dead'-air' space" Pronunciation: (ded'âr'), [key] an unventilated air space in which the air does not circulate. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. dead air dead-ball line Related Content Daily Word Quiz: clairvoyant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language