The Collaborative International Dictionary of English v.0.48:

Narceine \Nar"ce*ine\, n. [L. narce numbness, torpor, Gr. ?????:
   cf. F. narc['e]["i]ne.] (Chem.)
   An alkaloid found in small quantities in opium, and extracted
   as a white crystalline substance of a bitter astringent
   taste. It is a narcotic. Called also narceia.
   [1913 Webster]