1. Any of a class of organic compounds, such as acetone, characterized by having a carbonyl group in which the carbon atom is bonded to two other hydrocarbon groups and having the general formula R(CO)R′, where R may be the same as R′.
2. See ketone body.
[German Keton, shortening and alteration of Aceton, acetone : Latin acētum, vinegar; see ACETUM + German -on, n. suff. (alteration of -en, from Greek -ēnē).]
ke·tonic (-tŏnĭk) adj.
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