narceine

from The Century Dictionary.

• noun An alkaloid (C₂₃H₂₉NO₉) contained in opium.
• noun An acid coal-tar color of the monoazo type, prepared by combining diazotized sulphanilic acid with β-naph-thol and then treating the product with sodium bisulphite. It dyes wool orange in an acid bath, but is chiefly used in textile-printing.

from the GNU version of the Collaborative International Dictionary of English.

• noun (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.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun pharmacy An alkaloid contained in opium, occurring as fine white, silky crystals, slightly soluble in water, used as a substitute for morphine.