/ Dictionary / Index C Coolidge tube: Meaning and Definition of Find definitions for: Cool'idge tube" Pronunciation: [key] — Physics. Physics. a cathode ray tube, used for x-ray production, in which a beam of thermoelectrons is produced by heating a wire cathode. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Coolidge coolie Related Content Daily Word Quiz: foliage Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language