Synonyms for Marijuana (same or very similar meaning)
WordNet sense 1 (a strong-smelling plant from whose dried leaves a number of euphoriant and hallucinogenic drugs are prepared):
marihuana, ganja, Cannabis sativaWordNet sense 2 (the most commonly used illicit drug; considered a soft drug, it consists of the dried leaves of the hemp plant; smoked or chewed for euphoric effect):
cannabisFrom the ODE community, based on WordNetadd/edit