What does ketone mean?
In chemistry, a ketone is an organic compound characterized by a carbonyl group: a carbon atom double-bonded to oxygen and single-bonded to two other carbon atoms. This structure places ketones between aldehydes and carboxylic acids in the classification of carbonyl compounds. Familiar examples include acetone, used as a solvent and fuel additive, and acetophenone, used in the production of pharmaceuticals and fragrances. Ketones also occur naturally in the body, where they participate in metabolism, and some ketone bodies can become an important energy source when carbohydrate availability is low. The term is primarily used in chemistry, biochemistry, medicine, and nutrition. In technical writing, a ketone should be distinguished from a ketone functional group and from the metabolic condition known as ketosis. Although the word may appear uncommon in everyday speech, it names an important structural class of organic molecules and helps explain the properties of many widely used chemical substances.
nounAn organic compound containing a carbonyl group (C=O) whose carbon atom is bonded to two other carbon atoms. Ketones are a major class of organic compounds and include familiar substances such as acetone.
- Any organic compound whose carbonyl carbon is bonded to two carbon atoms.
"Acetone, a powerful solvent used to remove some paints and adhesives, is a simple ketone."
"The reaction converted the alcohol into a ketone."
"Blood tests showed elevated ketone levels, a sign that the body was using fat for energy."
The standard plural refers to multiple ketone compounds; in metabolism and nutrition, it may also refer collectively to ketone bodies.
"Several ketones are responsible for the characteristic aroma of many fruits and flowers."
The chemical family takes its name from a Greek word for a sea monster—an unexpectedly oceanic detour through organic chemistry.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does ketone come from?
Ketone entered English through the German word Keton, which was derived from the Greek kētōn, meaning a sea monster or large sea creature, ultimately connected with kētos, meaning sea or whale. Related English words include cetacean, cetology, and cetus. The marine origin of the chemical term is especially striking because ketones became prominent in the systematic study of organic compounds.
Related word forms
How ketone is actually used
In scientific contexts, ketone is a precise chemical designation, not a general term for every compound containing carbon and oxygen. In nutrition and metabolism, plural ketones is often used informally for ketone bodies associated with fasting, carbohydrate restriction, or related metabolic states.
Easily confused with ketone
A ketone is a chemical compound, whereas ketosis is the metabolic condition in which the body accumulates ketone bodies.