Definition of "addiction" []

• Compulsive physiological and psychological need for a habit-forming substance: a drug used in the treatment of heroin addiction. (noun)
• An instance of this: a person with multiple chemical addictions. (noun)
• The condition of being habitually or compulsively occupied with or or involved in something. (noun)
• An instance of this: had an addiction for fast cars. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The term addiction usually refers to both psychological and physical dependence on a drug, including alcohol."
• "My analogy regarding giving more tax dollars to Congress, likening it to heroin addiction, is quite apt."
• "The current directors of the agencies charged with studying drugs (the National Institute on Drug Abuse, or NIDA) and alcohol (the National Institute on Alcohol Abuse and Alcoholism, or NIAAA) have both voted for returning the term addiction to DSM-V."