/ Dictionary / Index R radiolysis: Meaning and Definition of Find definitions for: ra•di•ol•y•sis Pronunciation: (rā-dē-ol'u-sis), [key] — n. Chem. the dissociation of molecules by ionizing radiation. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: radiolysis (Thesaurus) radioluminescence radioman Related Content Daily Word Quiz: prevalent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language