Pharmacology. a chemical substance used in the treatment, cure, prevention, or diagnosis of disease or used to otherwise enhance physical or mental well-being.
(in federal law)
any substance recognized in the official pharmacopoeia or formulary of the nation.
any substance intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease in humans or other animals.
any article, other than food, intended to affect the structure or any function of the body of humans or other animals.
any substance intended for use as a component of such a drug, but not a device or a part of a device.
a habit-forming medicinal or illicit substance, especially a narcotic.
drugs,
chemical substances prepared and sold as pharmaceutical items, either by prescription or over the counter.
personal hygienic items sold in a drugstore, as toothpaste, mouthwash, etc.
Obsolete. any ingredient used in chemistry, pharmacy, dyeing, or the like.
to administer a medicinal drug to.
to stupefy or poison with a drug.
to mix (food or drink) with a drug, especially a stupefying, narcotic, or poisonous drug.
to administer anything nauseous to.
any synthetic, semisynthetic, or natural chemical substance used in the treatment, prevention, or diagnosis of disease, or for other medical reasons
a chemical substance, esp a narcotic, taken for the pleasant effects it produces
a commodity available in excess of the demands of the market
to mix a drug with (food, drink, etc)
to administer a drug to
to stupefy or poison with or as if with a drug
A chemical substance, especially one prescribed by a medical provider, that is used in the diagnosis, treatment, or prevention of a condition or disease. Drugs are prescribed for a limited amount of time, as for an acute infection, or on a regular basis for chronic disorders, such as hypertension.
A chemical substance such as a narcotic or a hallucinogen that affects the central nervous system and is used recreationally for perceived desirable effects on personality, perception, or behavior. Many recreational drugs are used illicitly and can be addictive.
First recorded in 1300–50; Middle English drogges (plural), from Middle French drogue, of obscure origin
From the Avestan word drauga
A drug is a medicine. Before you travel to India, your doctor may prescribe a drug to protect you from getting malaria. A substance that makes a change in your body is a drug. Most often, a drug is medicine prescribed by a doctor to protect a patient from illness, cure them, or relieve their pain. Drug also means an illegal substance taken simply for the way it makes the user feel. Drug is also a verb that describes both taking illegal drugs and giving someone a drug secretly, such as slipping it into their food or drink.
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
The trial of two potential treatments for Bundibugyo began in the DRC on July 2, and is evaluating the effectiveness of the monoclonal antibody MBP134 and the antiviral drug remdesivir, alone and in combination.
From Barron's • Jul. 9, 2026
The drug was intended to treat patients with transthyretin-mediated amyloid cardiomyopathy, a cardiovascular disease that results from proteins building up in the heart, and affects between 300,000 and 500,000 people globally, according to Ionis’s estimates.
From MarketWatch • Jul. 9, 2026
A continued drop in drug overdose deaths contributed to the low rate, while influenza and pneumonia now rank among the top 10 causes of death, according to a CDC preliminary report.
From The Wall Street Journal • Jul. 8, 2026
This mechanism is what enables combinatorial biosynthesis and allows bacteria to naturally generate multiple drug variants.
From Science Daily • Jul. 8, 2026
In any case, she refused to take the drug test and signed a paper for the termination of her parental rights to me instead.
From "Three Little Words: A Memoir" by Ashley Rhodes-Courter
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
