ke·​to | \ ˈkē-(ˌ)tō How to pronounce keto (audio) \

Definition of keto

 (Entry 1 of 3)

1 : of or relating to a ketone also : containing the characteristic chemical group of a ketone consisting of a carbonyl attached to two carbon atoms keto acids
2 : ketogenic sense 2 Since keto dieting is restrictive it's a good idea to consult with your doctor before starting.— Ted Kallmyer



Definition of keto (Entry 2 of 3)

: a ketogenic diet Salad is great for keto, but the dressing might not be. When in doubt, skip it.— John Nicholson Keto is a diet trend that cuts out carbohydrates and sugars to stop the blood sugar from spiking and have the body enter a state of ketosis, a process in which body burns fat for energy because it does not have enough carbohydrates to burn.— Dan Boudreaux

Definition of keto- (Entry 3 of 3)

: ketone : ketone body ketosis

Examples of keto in a Sentence

Recent Examples on the Web: Adjective Perhaps the parents in those keto baby groups are onto something. Christina Oehler,, "Can Keto Help With Fertility? One Man Thinks the Diet Got His Wife Pregnant," 20 Aug. 2019 Mummy Dogs These adorable pigs in a blanket from Step Away From The Carbs are perfect for keto dieters AND their kids. Christina Oehler,, "7 Keto Halloween Appetizers That Are Scary Good," 7 Oct. 2019 Those compounds are what cause keto breath: a metallic-tasting, somewhat stinky side effect. Jaclyn London, Ms, Rd, Cdn, Good Housekeeping, "9 Keto Diet Dangers Nutritionists Want You to Know About," 2 Jan. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'keto.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of keto


1891, in the meaning defined at sense 1


1994, in the meaning defined above

History and Etymology for keto


(sense 1) from construing of keto- as an adjective; (sense 2) by shortening


by shortening

Combining form

ket(one) + -o-

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Last Updated

13 Feb 2020

Cite this Entry

“Keto.” Dictionary, Merriam-Webster, Accessed 3 Apr. 2020.

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More Definitions for keto

ke·​to | \ ˈkēt-(ˌ)ō How to pronounce keto (audio) \

Medical Definition of keto

: of or relating to a ketone also : containing a ketone group

More from Merriam-Webster on keto

Rhyming Dictionary: Words that rhyme with keto

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