/ Dictionary / Index M methyl group: Meaning and Definition of Find definitions for: meth'yl group" Pronunciation: [key] the univalent group CH−, derived from methane. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. methylglyoxal methylheptenone Related Content Daily Word Quiz: diligent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language