/ Dictionary / Index M methyl methacrylate: Meaning and Definition of Find definitions for: meth'yl methac'rylate Pronunciation: [key] a colorless, volatile, flammable, water-insoluble, liquid, unsaturated ester, CHO, that polymerizes readily to a clear plastic. Cf. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. methylmercury methylnaphthalene 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