From WordNet (r) 2.0 (August 2003) [wn]:
ganja
n 1: a strong-smelling plant from whose dried leaves a number of
euphoriant and hallucinogenic drugs are prepared [syn:
marijuana, marihuana, Cannabis sativa]
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 [syn: cannabis,
marijuana, marihuana]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Ganja \Gan"ja\, n. [Hind. g[=a]njh[=a].]
The dried hemp plant, used in India for smoking. It is
extremely narcotic and intoxicating.
[1913 Webster]