/ Dictionary / Index E ethyl: Meaning and Definition of Find definitions for: eth•yl Pronunciation: (eth'ul), [key] — adj. containing the ethyl group, as ethyl ether, CHO. —n. a type of antiknock fluid, containing tetraethyl lead and other ingredients for a more even combustion. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: ethyl (Thesaurus) ethrog ethyl acetate Related Content Daily Word Quiz: mamba Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language