/ Dictionary / Index I internal conversion: Meaning and Definition of Find definitions for: inter'nal conver'sion Pronunciation: [key] — Physics. Physics. the emission of an electron by an atom with an excited nucleus, occurring as a result of the transfer of energy from the nucleus to the electron. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. internal-combustion engine internal ear Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language