Definition of "drug" []

• A substance used in the diagnosis, treatment, or prevention of a disease or as a component of a medication. (noun)
• Such a substance as recognized or defined by the U.S. Food, Drug, and Cosmetic Act. (noun)
• A chemical substance, such as a narcotic or hallucinogen, that affects the central nervous system, causing changes in behavior and often addiction. (noun)
• Obsolete A chemical or dye. (noun)
• To administer a drug to. (verb-transitive)

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.

• "Officials usually avoid even the term "drug cartels," and instead refer to them as "organized crime," perhaps more accurate now that much of the gangs' income comes from extortion and kidnapping."
• "The term drug discovery tools usually refers to high-content screening (HCS) and analysis and is composed of those applications that require sufficient levels of sample throughput, whereby complex cellular events and phenotypes can be studied."
• "The term drug-resistant TB, or DR-TB is used to describe those strains of TB which show resistance to one or more of the common first-line drugs."