Cannabis refers to leaves, buds, flowers and resin from the cannabis plant, Cannabis sativa, a native of central Asia.
The plant contains numerous psychoactive compounds called cannabinoids, the most potent of which is delta-9-tetrahydrocannabinol (THC). Cannabis is usually smoked in the form of dried leaves and buds, or as a dried resin (hashish). Smoked in moderate quantities, cannabis can produces feelings of fuzzy mellowness and general well-being. It can interfere with memory and increase appetite ("the munchies"). Some users experience nausea, anxiety and paranoia. If eaten, the resin can be powerfully hallucinogenic. No fatal dose has ever been recorded in humans
Other /More definition:
Cannabis refers to the substance that causes feelings of well-being, perceptual distortions, and paranoid thinking. It is the hemp plant from which marijuana, hashish, and THC are derived. Cannabis is also known as Cannabis Sativa