The rune is called Thurs (Old Norse Þurs "giant", from a reconstructed Common Germanic *Þurisaz) in the Icelandic and Norwegian rune poems. In the Anglo-Saxon rune poem it is called thorn, whence the name of the letter þ derived. It is transliterated as þ, and has the sound value of a voiceless dental fricative (the English sound of th as in thing).

The rune is an adoption of the Latin letter D (while the d rune takes its shape from an Italic variant of the letter san). It is absent from the earliest Vimose inscriptions, but it is found in the Thorsberg chape inscription, dated to ca. AD 200.