/ Dictionary / Index E ethynylation: Meaning and Definition of Find definitions for: e•thy•nyl•a•tion Pronunciation: (e-thīn"l-ā'shun), [key] — n. Chem. the process of introducing the ethynyl group into a compound. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. ethynyl ethynyl group Related Content Daily Word Quiz: hedonist Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language