Definition of: opium

(ō′pē·əm) noun
A milky exudation from the unripe capsules of the opium poppy (Papaver somniferum), containing a mixture of about 20 alkaloids, the most important of which is morphine. It is a powerful narcotic, with a sticky, gumlike body, bitter taste, and heavy odor. [<L <Gk. opion opium, dim. of opos vegetable juice]