/ Dictionary / Index M menthaceous: Meaning and Definition of Find definitions for: men•tha•ceous Pronunciation: (men-thā'shus), [key] — adj. belonging to the Menthaceae, a former name for the plant family Labiatae. Cf. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Mentes menthene Related Content Daily Word Quiz: cautious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language