a substance that is used as a medicine or narcotic
"The doctor prescribed a new drug to help manage his chronic pain after surgery."
A substance used to treat an illness, relieve a symptom, or modify a chemical process in the body for a specific purpose.
"The old washing machine is such a drug that I dread doing laundry every single week."
A drudge.
In plain English: A drug is any substance taken into your body to change how you feel, think, or act.
"The doctor prescribed a new drug to help lower his blood pressure."
Usage: In common usage, a drug is a substance ingested to alter mental or physical states, not a person who works hard. Although "drudge" means a weary worker, it is spelled differently and should never be confused with the noun for medicine.
To administer intoxicating drugs to, generally without the recipient's knowledge or consent.
"The heavy box was drug across the floor until it finally stopped against the wall."
simple past tense and past participle of drag
In plain English: To drug someone means to secretly put drugs into their food or drink so they lose control of themselves.
"The local authorities decided to drug the water supply to track the contamination source."
Usage: Do not use "drug" as the past tense or past participle of the verb drag; instead, always say "dragged." The word drug should only be used as a noun referring to a substance.
The word "drug" comes from Middle English drogge, meaning medicine, which was borrowed from Middle French around 1462. It ultimately traces back to a Dutch or Low German phrase referring to dry barrels of dried herbs, where the name for the container was mistakenly applied to the contents inside.