/ Dictionary / Index T tolyl group: Meaning and Definition of Find definitions for: tol'yl group" Pronunciation: [key] — Chem. Chem. any of three univalent, isomeric groups having the formula CH–, derived from toluene. Also called tol&prim;yl rad&sec;ical. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. tolyl tom Related Content Daily Word Quiz: modify Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language