noun, often capitalized, often attributive
\ ˈkā How to pronounce k (audio) \
plural k's or ks\ ˈkāz How to pronounce k (audio) \

Definition of k

 (Entry 1 of 4)

1a : the 11th letter of the English alphabet
b : a graphic representation of this letter
c : a speech counterpart of orthographic k
2 : a graphic device for reproducing the letter k
3 : one designated k especially as the 11th in order or class
4 : something shaped like the letter K
5 : a unit vector parallel to the z-axis
6 [kilo-] : thousand a salary of $24K
7 [kilo-] : a unit of computer storage capacity equal to 1024 bytes uses 350K of disk space
8 capitalized [struck] : strikeout

Definition of k (Entry 2 of 4)

1 karat
2 kindergarten
3 king
4 kitchen
5 knit
6 knot
7 koruna
8 kosher often enclosed in a circle
9 kyat

Definition of K (Entry 3 of 4)

1 Kelvin
2 kilometer



Definition of K (Entry 4 of 4)


Examples of k in a Sentence

Noun There is one k in “book.” The word ends in k. She earned a salary of $30K. The program uses 350K of disk space. The pitcher had more than 10 Ks in his last game.
See More

First Known Use of k


before the 12th century, in the meaning defined at sense 1a

History and Etymology for k


New Latin kalium

Keep scrolling for more

Learn More about k

Time Traveler for k

Time Traveler

The first known use of k was before the 12th century

See more words from the same century

Statistics for k

Cite this Entry

“K.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/k. Accessed 3 Mar. 2021.

Style: MLA
MLA Chicago APA Merriam-Webster

Keep scrolling for more

More Definitions for k


noun, often capitalized
\ ˈkā How to pronounce k (audio) \
plural k's or ks\ ˈkāz \

Kids Definition of k

1 : the eleventh letter of the English alphabet
3 : kilobyte



Medical Definition of K

1 dissociation constant; ionization constant
2 [New Latin kalium] potassium
3 kelvin

More from Merriam-Webster on k

Nglish: Translation of k for Spanish Speakers

Comments on k

What made you want to look up k? Please tell us where you read or heard it (including the quote, if possible).


Test Your Vocabulary

February 2021 Words of the Day Quiz

  • squirrel in winter
  • Which is a synonym of perdure?
Name That Thing

Test your visual vocabulary with our 10-question challenge!

 AlphaBear 2

Spell words. Make bears.

Love words? Need even more definitions?

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