/ Dictionary / Index M mass spectroscope: Meaning and Definition of Find definitions for: mass' spec'troscope Pronunciation: [key] an instrument used to determine the masses of small, electrically charged particles. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. mass spectrometer mass spectrum Related Content Daily Word Quiz: exemplary Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language