/ Dictionary / Index M microgram: Meaning and Definition of Find definitions for: mi•cro•gram Pronunciation: (mī'kru-gram"), [key] — n. a unit of mass or weight equal to one millionth of a gram, used chiefly in microchemistry. Symbol: &mgr;g mi•cro•gram Pronunciation: (mī'kru-gram"), [key] — n. micrograph (def. 2). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: microgram (Thesaurus) microgamete micrograph Related Content Daily Word Quiz: abdicate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language