cannabis
n. any of three related plant species (Cannabis sativa, C. indica, or C. ruderalis) whose dried flowering or fruiting tops or leaves are widely used as a recreational drug, known as marijuana. The principal psychoactive agent in these plants, delta-9-tetrahydrocannabinol (THC), is concentrated in the resin, most of which is in the plants’ flowering tops. When smoked, THC is rapidly absorbed into the blood and almost immediately distributed to the brain, causing the rapid onset of subjective effects that last 2 to 3 hours. These effects include a sense of euphoria or well-being, easy laughter, perceptual distortions, impairment of concentration and short-term memory, and craving for food. Adverse effects of anxiety or panic are not uncommon, and hallucinations may occur with high doses (see also cannabis-induced psychotic disorder; cannabis intoxication). Tolerance to the effects of THC develops
with repeated use, and a withdrawal syndrome has been identified. The most potent marijuana preparation is hashish, which consists of pure resin. A less potent preparation is sinsemilla, also called ganja; it is made from the plants’ flowering tops. The weakest preparation is bhang. Also called hemp.