toxic
Meaning of toxic: Toxic describes a substance capable of causing harm to the body, with the likelihood and severity of harm depending largely on the amount involved.
Definition of toxic
Toxic describes anything having to do with poison or a substance capable of causing harm to the body. A toxic substance can be a naturally occurring compound, a manufactured chemical, or a medication, and whether it actually causes harm depends heavily on factors such as the amount involved, the duration of exposure, and the way it enters the body.
Many substances that are toxic at a high dose are harmless or even beneficial at a lower one, a principle that underlies how medications are dosed to achieve a therapeutic effect while limiting toxic effects. A substance's toxic effects can also vary depending on which organ or system is most affected.
Toxic is closely related to the noun toxicity, which describes the degree or extent of a substance's capacity to cause harm, and to toxin, a term generally reserved for a poisonous substance produced by a living organism.
Used in a sentence
The patient's symptoms were evaluated for a possible toxic reaction to the newly started medication.
Good to know
A toxic effect is usually a matter of degree rather than an all or nothing property, since the same substance can be harmless, therapeutic, or toxic depending mainly on the dose and circumstances of exposure.
Word origin
Where “toxic” comes from
Formed from Greek toxikon, meaning poison, from toxon, meaning bow.