'THC' definitions:

Definition of 'THC'

noun

Psychoactive substance present in marijuana [syn: tetrahydrocannabinol, THC]

From: GCIDE

tetrahydrocannabinol \tet`ra*hy`dro*can*nab"i*nol\ (t[e^]t`r[.a]*h[imac]`dr[-o]*k[a^]n*n[a^]b"[i^]n[add]l), 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 [Delta]1-3,4-trans isomer, also called [Delta]9-THC, with small amounts of the [Delta]6-3,4-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]

From: GCIDE

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]