n :  a poisonous fetid Old World herb of the genus Hyoscyamus (H. niger) that has sticky hairy dentate leaves and yellowish brown flowers, contains the alkaloids hyoscyamine and scopolamine, and is the source of hyoscyamus - called also black henbane , insane root  .
 
 
 
Published under license with Merriam-Webster, Incorporated.  © 1997-2024.