/ Dictionary / Index A allylic: Meaning and Definition of Find definitions for: al•lyl•ic Pronunciation: (u-lil'ik), [key] — adj. of, pertaining to, or characteristic of the allyl group. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: allylic (Thesaurus) allyl group allyl mercaptan Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language