/ Dictionary / Index P photoneutron: Meaning and Definition of Find definitions for: pho•to•neu•tron Pronunciation: (fō"tu-n'tron, -ny'-), [key] — n. Physics. a neutron emitted from a nucleus during photodisintegration. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. photonegative photonic Related Content Daily Word Quiz: fervor Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language