/ Dictionary / Index E ethylene oxide: Meaning and Definition of Find definitions for: eth'ylene ox'ide Pronunciation: [key] — Chem. Chem. a colorless, odorless, gaseous, toxic, ring compound, CHO, usually obtained by the oxidation of ethylene: used chiefly in the synthesis of ethylene glycol. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. ethylene group ethylene series Related Content Daily Word Quiz: serendipity Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language