/ Dictionary / Index M mmho: Meaning and Definition of Find definitions for: mmho Pronunciation: [key] millimho; millimhos. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. mm Hg MMPI Related Content Daily Word Quiz: maritime Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language