/ Dictionary / Index T thimerosal: Meaning and Definition of Find definitions for: thi•mer•o•sal Pronunciation: (thī-mûr'u-sal", -mer'-), [key] — n. Pharm. a cream-colored, crystalline, water-soluble powder, CHHgNaOS, used chiefly as an antiseptic. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: thimerosal (Thesaurus) thimbleweed Thimphu Related Content Daily Word Quiz: panacea Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language