/ Dictionary / Index C coniine: Meaning and Definition of Find definitions for: co•ni•ine Pronunciation: (kō'nē-ēn", -in, -nēn), [key] — n. a volatile, highly poisonous alkaloid, CHN, constituting the active principle of the poison hemlock. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. coniferous conirostral Related Content Daily Word Quiz: panacea Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language