www.google.com great tool....i think they even have a image search.
* Withdrawal -- Presence and severity of characteristic withdrawal symptoms.
* Reinforcement -- Substance's ability, in human and animal tests, to get users to take it repeatedly, and instead of other substances.
* Tolerance -- Amount of substance needed to satisfy increasing cravings, and level of plateau that is eventually reached.
* Dependence -- Difficulty in ending use of substance, relapse rate, percentage of people who become addicted, addicts self-reporting of degree of need for substance, and continued use in face of evidence that it causes harm.
* Intoxication -- Level of intoxication associated with addiction, personal and social damage that substance causes.
in case anybody else is wondering wtf is meant by 'reinforcement'