/ Dictionary / Index A artificial radioactivity: Meaning and Definition of Find definitions for: artifi'cial radioactiv'ity Pronunciation: [key] — Physics. Physics. radioactivity introduced into a nonradioactive substance by bombarding the substance with charged particles. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. artificial person artificial reality Related Content Daily Word Quiz: cygnet Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language