/ Dictionary / Index H heterocyclic: Meaning and Definition of Find definitions for: het•er•o•cy•clic Pronunciation: (het"ur-u-sī'klik, -sik'lik), [key] — adj. Chem. of or pertaining to the branch of chemistry dealing with cyclic compounds in which at least one of the ring members is not a carbon atom (contrasted with homocyclic). noting such compounds, as ethylene oxide, CHO. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: heterocyclic (Thesaurus) heteroclite heterocyst Related Content Daily Word Quiz: voracious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language