/ Dictionary / Index A atmospheric window: Meaning and Definition of Find definitions for: at'mospher'ic win'dow Pronunciation: [key] — Astron. Astron. any of the wavelengths at which electromagnetic radiation from space can penetrate the earth's atmosphere. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. atmospheric tide Atna Related Content Daily Word Quiz: gregarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language