[1] : The Collaborative International Dictionary of English v.0.48

marijuana \marijuana\ n.
   1. a strong-smelling asian plant cannabis sativa, also
      called hemp, from which a number of euphorogenic and
      halucinogenic drugs are prepared. the euphoric effect is
      predominently due to tetrahydrocannabinol thc. also
      spelled marihuana.

   syn: cannabis, ganja, pot, grass, marihuana, cannabis
        sativa.
        wordnet 1.5

   2. the dried leaves or the female flowers of the hemp plant,
      which is smoked or chewed to obtain a euphoric effect. the
      flowers usually have a higher concentration of the active
      ingredient, tetrahydrocannabinol.

   syn: cannabis, ganja, pot, grass, marihuana, dope, weed,
        gage, sess, sens, smoke, skunk, mary jane.
        wordnet 1.5
see also:
cannabis sativa hemp tetrahydrocannabinol thc marihuana cannabis sativa 

[2] : WordNet (r) 2.0

marihuana
     n 1: a strong-smelling plant from whose dried leaves a number of
          euphoriant and hallucinogenic drugs are prepared syn: marijuana,
           ganja, 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,
         ganja
see also:
marijuana ganja cannabis sativa cannabis 

Marihuana >> M Words
Marihuana, definition of term: Marihuana
marihuana_pag1.html