right|thumb|300px|The evolution of the rune in the elder futhark during the centuries
The k-rune (Younger Futhark , Anglo-Saxon futhorc ) is called Kaun in both the Norwegian and Icelandic rune poems, meaning "ulcer". The reconstructed Proto-Germanic name is *Kauną. It is also known as Kenaz ("torch"), based on its Anglo-Saxon name.
The Elder Futhark shape is likely directly based on Old Italic c (14px|C, 𐌂) and on Latin C. The Younger Futhark and Anglo-Saxon Futhorc shapes have parallels in Old Italic shapes of k (14px|K, 𐌊) and Latin K (compare the Negau helmet inscription). The corresponding Gothic letter is 𐌺 k, called kusma.
The shape of the Younger Futhark kaun rune () is identical to that of the "bookhand" s rune in the Anglo-Saxon futhorc.
The rune also occurs in some continental runic inscriptions. It has been suggested that in these instances, it represents the ch /χ/ sound resulting from the Old High German sound shift (e.g. elch in Nordendorf II).
{| class="wikitable"
| Rune Poem:
| English Translation:
|-
|
Old Norwegian
<br /> Kaun er barna bǫlvan;
<br />bǫl gørver nán fǫlvan.
|
<br />Ulcer is fatal to children;
<br />death makes a corpse pale.
|-
|
Old Icelandic
<br /> Kaun er barna böl
<br />ok bardaga [för]
<br />ok holdfúa hús.
<br />flagella konungr.
|
<br />Disease fatal to children
<br />and painful spot
<br />and abode of mortification.
|-
|
Old English
<br /> Cen bẏþ cƿicera gehƿam, cuþ on fẏre
<br />blac ond beorhtlic, bẏrneþ oftust
<br />ðær hi æþelingas inne restaþ.
|
<br />The torch is known to every living man
<br />by its pale, bright flame; it always burns
<br />where princes sit within.
|-
|colspan=2 |Notes:
- The Icelandic poem is glossed with Latin flagella "whip".
- The Anglo-Saxon poem gives the name cen "torch". <!-- (Which was perhaps an expansion upon the "burning" of the ulcers or chancres described in the Scandinavian poems, or possibly because the original meaning had become lost.) -->
|}