Thorn or þorn (Þ, þ) , is a letter in the Old English , Old Norse , and Icelandic alphabets , as well as some dialects of Middle English . It was also used in medieval Scandinavia , but was later replaced with the digraph th. The letter originated from the rune ᚦ in the Elder Fuþark , called thorn in the Anglo-Saxon and thorn or thurs (" giant ") in the Scandinavian rune poems , its reconstructed Proto-Germanic name being Thurisaz . It has the sound of either a voiceless dental fricative [θ], like th as in the English word thick , or a voiced dental fricative [ð], like th as in the English word the . Modern Icelandic usage excludes the latter, which is instead represented with the letter eth (Ð, ð), though it has a voiceless allophone [θ], which occurs in certain positions within a phrase. In its typography , the thorn is one of the few characters in a Latin-derived alphabet whose modern lower-case form has greater height than the capital in its normal (...