/ Dictionary / Index M monoatomic: Meaning and Definition of Find definitions for: mon•o•a•tom•ic Pronunciation: (mon"ō-u-tom'ik), [key] — adj. Chem. monatomic. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: monoatomic (Thesaurus) monoammonium phosphate monobasic Related Content Daily Word Quiz: agitated Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language