/ Dictionary / Index C Crookes radiometer: Meaning and Definition of Find definitions for: Crookes' radiom'eter Pronunciation: [key] — Optics. Optics. radiometer (def. 1). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. crookesite Crookes tube Related Content Daily Word Quiz: confectionery Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language