What does overdose mean?
Overdose is a noun and verb referring to an excessive dose of a drug, medicine, chemical, or other substance. As a noun, it describes either the quantity taken or the resulting medical emergency; as a verb, it describes taking too much of a substance or giving it to someone in an amount that may cause serious harm. The word is especially associated with medicines and illicit drugs, but it can apply to any substance whose quantity becomes dangerous. In public discussion, drug overdose is a standard phrase, and overdose symptoms and fatal overdose are also common. The term can be used for both accidental and intentional cases, so the surrounding context usually determines whether the event is being described neutrally or as a self-harm or poisoning incident. Overdose is more precise than simply saying too much, because it implies a quantity that exceeds a safe or intended limit.
An excessive dose of a drug, medicine, chemical, or other substance that may cause illness, injury, or death; also the act or event of taking or receiving such a dose.
"Public-health officials reported a sharp increase in accidental overdoses."
Usually singular in the sense of a particular incident, though plural overdoses is common when referring to multiple cases.
To take or administer a dose of a substance in an amount that is excessive or dangerous.
"The doctor warned that combining the two medicines could cause a patient to overdose."
Often used in medical and safety contexts. It can be transitive, as in overdose someone, or intransitive, as in overdose on medication.
The plural is used for multiple incidents, cases, quantities, or acts of taking or receiving an excessive dose.
"The hospital recorded two overdoses during the night."
An overdose is defined by the dose, not by the substance: even a familiar medicine can become dangerous in an excessive quantity.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does overdose come from?
The word combines the prefix over-, meaning “in excessive amount,” with the noun dose, which comes through Old French from Latin dosis, a borrowing from Greek. The compound developed in medical usage to name an excessive or dangerous quantity of a substance. The prefix over- is also the source of many English words such as overcome and overlap, while dose and dosage belong to the same lexical family. The verb form acquired its own stress pattern in standard American pronunciation.
Related word forms
How overdose is actually used
The noun is commonly used in medical, toxicological, and public-health contexts, especially in the expression drug overdose. The verb is transitive when it means to give someone too much of a substance and intransitive when it means to take too much. It can describe accidental as well as deliberate incidents.
Easily confused with overdose
An overdose is an excessive amount of a substance, whereas an underdose is an amount smaller than intended or safe.