/ Dictionary / Index M methylmercury: Meaning and Definition of Find definitions for: meth•yl•mer•cu•ry Pronunciation: (meth"ul-mûr'kyu-rē), [key] — n. Chem. any of several extremely toxic organometallic compounds, Hg(CH), formed from metallic mercury by the action of microorganisms and capable of entering the food chain: used as seed disinfectants. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. methyl lactate methyl methacrylate Related Content Daily Word Quiz: penchant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language