/ Dictionary / Index P positive ray: Meaning and Definition of Find definitions for: pos'itive ray" Pronunciation: [key] — Physics. Physics. a stream of positive ions traveling from a metallic anode to the cathode in a gas-discharge tube. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. positive organ positivism Related Content Daily Word Quiz: frugal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language