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 So, are non-keto dieters missing out on the next big thing? Zee Krstic, Good Housekeeping, 1 Oct. 2020 But there are ways for those who follow vegan, gluten-free or keto diets to make it through with substitutes, home cooking and a lot of patience. Kelly Lawler, USA TODAY, 28 Mar. 2020 Perhaps the parents in those keto baby groups are onto something. Christina Oehler,, 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 Oct. 2019 Those compounds are what cause keto breath: a metallic-tasting, somewhat stinky side effect. Jaclyn London, Ms, Rd, Cdn, Good Housekeeping, 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.

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-

Learn More About keto

Dictionary Entries Near keto




See More Nearby Entries 

Statistics for keto

Cite this Entry

“Keto.” Dictionary, Merriam-Webster, Accessed 6 Jul. 2022.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

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


Test Your Vocabulary

Words Named After People

  • name tags
  • Namesake of the leotard, Jules Léotard had what profession?
Spell It

Can you spell these 10 commonly misspelled words?

Universal Daily Crossword

A daily challenge for crossword fanatics.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!