Weed, mary, ganja, pot, cannabis, hemp. Dope! Marijuana or marihuana is the cannabis plant. Some jurisdictions recognize marijuana as a distinctive strain of cannabis, the other being hemp. Some say it's illegal. Some say it's medicine. Probably it's something inbetween. The use of marihuana in American English increased in the 1930s. It has been suggested that the word was promoted by opponents of the drug, who wanted to stigmatize it with a foreign-sounding name.