/ Dictionary / Index P positron emission tomography: Meaning and Definition of Find definitions for: pos'itron emis"sion tomog"raphy Pronunciation: [key] the process of producing a PET scan. Cf. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. positron positronium Related Content Daily Word Quiz: inutiae Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language