The k-rune ᚲ (Younger Futhark ᚴ, Anglo-Saxon Futhorc ᚳ) is called Kaun in both the Norwegian and Icelandic rune poems, meaning "ulcer". The reconstructed Proto-Germanic name is Kaunan.

• Norwegian:

ᚴ Kaun er barna bǫlvan;

bǫl gørver nán fǫlvan.

Ulcer is fatal to children;

death makes a corpse pale.

• Icelandic (glossed as Latin flagella "whip"):

ᚴ Kaun er barna böl

ok bardaga [för]

ok holdfúa hús.

flagella konungr.

Disease fatal to children

and painful spot

and abode of mortification.

In scenarios that assume a system of divination surrounding the Old Futhark, this is clearly seen as one of the less auspicious runes.

The corresponding Gothic letter is 𐌺 k, called kusma.

The Anglo-Saxon rune poem gives a name cen "torch", probably because the original name was no longer understood:

ᚳ Cen byþ cwicera gehwam, cuþ on fyre

blac ond beorhtlic, byrneþ oftust

ðær hi æþelingas inne restaþ.

The torch is known to every living man

by its pale, bright flame; it always burns

where princes sit within.