opium

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A bitter, yellowish-brown, strongly addictive narcotic drug prepared from the dried juice of unripe pods of the opium poppy and containing alkaloids such as morphine, codeine, and papaverine.
2. n. Something that numbs or stupefies.

Century Dictionary and Cyclopedia

1. n. The inspissated juice of Papaver somniferum, a poppy cultivated from early antiquity for the sake of this product. See poppy and Papaver. The opium exudes as a milky juice from shallow incisions made in the partly ripened capsules or heads still on the plant. It soon thickens, is collected by scraping, and kneaded into a homogeneous mass, forming then a reddish-brown sticky gum-like substance of bitter taste and peculiar odor. Opium was known to the Greeks, but was not much used before the seventeenth century; at present it is the most Important of all medicines, and its applications the most multifarious, the chief of them being for the relief of pain and the production of sleep. Its habitual use is disastrous and difficult to break up. It is classed as a stimulant narcotic, acting almost exclusively on the central nervous system when taken internally; in large quantities it is a powerful narcotic poison, resulting in a coma characterized by great contraction of the pupils, insensibility, and death. The chief active principle of opium is morphia, but it also contains at least sixteen other alkaloids, some of which have similar properties. (See narcotine.) Though opium can be produced in Europe, the United States, etc., its commercial production is limited to countries where labor is cheap and the drug in common use, namely Turkey, Persia, Egypt, India, and China. The Western market is supplied largely from Asia Minor. The Indian export goes chiefly to China.

Wiktionary

1. n. uncountable A yellow-brown, addictive narcotic drug obtained from the dried juice of unripe pods of the opium poppy, Papaver somniferum, and containing alkaloids such as morphine, codeine, and papaverine.
2. n. countable Anything that numbs or stupefies.

GNU Webster's 1913

1. n. (Chem.) The inspissated juice of the Papaver somniferum, or white poppy.

WordNet 3.0

1. n. an addictive narcotic extracted from seed capsules of the opium poppy