/ Dictionary / Index M mercurialism: Meaning and Definition of Find definitions for: mer•cu•ri•al•ism Pronunciation: (mur-kyoor'ē-u-liz"um), [key] — n. Pathol. poisoning by mercury. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. mercurial barometer. mercurialize Related Content Daily Word Quiz: clairvoyant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language