/ Dictionary / Index A air casing: Meaning and Definition of Find definitions for: air' cas"ing Pronunciation: [key] a casing for the funnel of a powered vessel, large enough to provide an air space all around the funnel. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. air carrier air castle Related Content Daily Word Quiz: eureka Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language