/ Dictionary / Index A Aston dark space: Meaning and Definition of Find definitions for: As'ton dark' space" Pronunciation: [key] — Physics. Physics. the dark region between the cathode and the cathode glow in a vacuum tube, occurring when the pressure is low. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Aston astonied Related Content Daily Word Quiz: blithesome Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language