/kēˈtōsis/
Noun
1. A state of elevated levels of ketone bodies in the body. (wikipedia.org)
2. A metabolic state in which the body produces ketones to be used as fuel by some organs so that glycogen can be reserved for organs that depend on it. This condition occurs during times of fasting, starvation, or while on a ketogenic weight-loss diet. (wiktionary.org)
3. Metabolic production of abnormal amounts of ketones. A consequence of diabetes melittus. (biology-online.org)
Word origin: From keto-, comb. form of ketone, from German keton, coined in 1848 by German chemist Leopold Gmelin (1788-1853) from German Aketon, from French acétone + –osis, denoting “a state of disease.”