Breadcrumb Home > Dictionary > Index A air duct: Meaning and Definition of Find definitions for: air' duct" Pronunciation: [key] an enclosure, usually of sheet metal, that conducts heated or conditioned air. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. air-dry -aire ✖ Related Content Daily Word Quiz: careening Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language