/ Dictionary / Index H hyoscyamine: Meaning and Definition of Find definitions for: hy•os•cy•a•mine Pronunciation: (hī"u-sī'u-mēn", -min), [key] — n. Pharm. a poisonous alkaloid, CHNO, obtained from henbane and other solanaceous plants, used as a sedative, analgesic, mydriatic, and antispasmodic. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: hyoscyamine (Thesaurus) hyoscine hyoscyamus Related Content Daily Word Quiz: innocuous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language