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 

tetrahydrocannabinol \tet`rahy`drocannab"inol\
   te^t`r.ahimac`dr-oka^nna^b"i^naddl, n.
   chem.  med.
   a chemical substance c21h20o2 which is produced by the
   hemp plant cannabis sativa, and is the physiologically
   active agent of dried preparations of that plant, called
   variously marijuana, hashish, ganja, hemp, etc.; also called
   thc. it causes the euphoric effect for which the
   preparations are smoked or chewed. it is used in medicine in
   a purified form as an antiemetic an antinausea agent,
   especially in conjunction with chemotherapy of cancer. it
   occurs primarily as the delta1-3,4-trans isomer, also
   called delta9-thc, with small amounts of the
   delta6-3,4-trans isomer detectable at about 1. it is a
   controlled substance, classified as a hallucinogen, and its
   possession or distribution is illegal in almost all states of
   the united states. --mi11
   pjc
see also:
c21h20o2 thc delta9-thc 

thc
     n : psychoactive substance present in marijuana syn: tetrahydrocannabinol
see also:
tetrahydrocannabinol