K

Egyptian hieroglyph D	Proto-Semitic K	Phoenician K	Etruscan K	Greek Kappa	Latin K

The letter K comes from the Greek letter Κ (kappa), which was taken from the Semitic kaph, the symbol for an open hand.[2] This, in turn, was likely adapted by Semitic tribes who had lived in Egypt from the hieroglyph for "hand" representing /ḏ/ in the Egyptian word for hand, ⟨ḏ-r-t⟩ (likely pronounced /ˈcʼaːɾat/ in Old Egyptian). The Semites evidently assigned it the sound value /k/ instead, because their word for hand started with that sound.[3]

In the earliest Latin inscriptions, the letters C, K and Q were all used to represent the sounds /k/ and /ɡ/ (which were not differentiated in writing). Of these, Q was used before a rounded vowel (e.g. ⟨EQO⟩ 'ego'), K before /a/ (e.g. ⟨KALENDIS⟩ 'calendis'), and C elsewhere. Later, the use of C and its variant G replaced most usages of K and Q. K survived only in a few fossilized forms such as Kalendae, "the calends".[4]

After Greek words were taken into Latin, the Kappa was transliterated as a C. Loanwords from other alphabets with the sound /k/ were also transliterated with C. Hence, the Romance languages generally use C, in imitating Classical Latin's practice, and have K only in later loanwords from other language groups. The Celtic languages also tended to use C instead of K, and this influence carried over into Old English.

¹ Also for encodings based on ASCII, including the DOS, Windows, ISO-8859 and nMacintosh families of encodings.

• "K" replacing "C" in satiric misspelling.
• K is the unit symbol for the kelvin, used to measure thermodynamic temperature (note: degree sign is not used with kelvin scale).
• K is the chemical symbol for the element potassium (K is an abbreviation of kalium, the Latin name for potassium).
• Triangle K.
• Unit prefix k, meaning 1000 times.
• Josef K is the name of the principal character in Franz Kafka's novel The Trial.
• In chess notation, the letter K represents the King (WK for White King, BK for Black King).
• In baseball scoring, the letter K is used to represent a strikeout. A forwards oriented K represents a "strikeout swinging"; a backwards oriented K () represents a "strikeout looking".
• As abbreviation for OK, often used in emails and short text messages.
• K is used as a slang term for Ketamine among recreational drug users.
• In the CMYK color model, K represents black ink.
• In International Morse code it is used to mean "over".[10]
• In fracture mechanics, K is used to represent the stress intensity factor.
• In physics, k usually stands for Boltzmann's constant
• K (logic).
• K is used colloquially to mean kilometre (as in "a 10K run").
• When expressing amounts of money, $20K means twenty thousand dollars.
• In the United Kingdom under the old system (before 2001), a licence plate that begins with "K" for example "K123 XYZ" would correspond to a vehicle registered between August 1, 1992 and July 31, 1993. Again under the old system, a licence plate that ends with "K" for example "ABC 123K" would correspond to a vehicle that was registered between August 1, 1971 and July 31, 1972.

• Media related to K at Wikimedia Commons
• The dictionary definition of K at Wiktionary
• The dictionary definition of k at Wiktionary