/ Dictionary / Index H hydrargyrum: Meaning and Definition of Find definitions for: hy•drar•gy•rum Pronunciation: (hī-drär'jur-um), [key] — n. mercury. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: hydrargyrum (Thesaurus) hydrargyrism hydrase Related Content Daily Word Quiz: philtrum Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language