/ Dictionary / Index M microthin: Meaning and Definition of Find definitions for: mi•cro•thin Pronunciation: (mī'krō-thin"), [key] — adj. extremely or, sometimes, microscopically thin: a microthin layer of aluminum. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. microtherm microtome Related Content Daily Word Quiz: gregarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language