Eth

Eth (, uppercase: Ð, lowercase: ð; also spelled edh or eð), known as ðæt in Old English, is a letter used in Old English, Middle English, Icelandic, Faroese (in which it is called edd), and Elfdalian.

It was also used in Scandinavia during the Middle Ages, but was subsequently replaced with $⟨Ð⟩$, and later $⟨ð⟩$.

It is often transliterated as $⟨dh⟩$.

The lowercase version has been adopted to represent a voiced dental fricative in the International Phonetic Alphabet.

Faroese
In Faroese, $⟨d⟩$ is not assigned to any particular phoneme and appears mostly for etymological reasons, but it indicates most glides. When $⟨d⟩$ appears before $⟨ð⟩$, it is in a few words pronounced. In the Faroese alphabet, $⟨ð⟩$ follows $⟨r⟩$.

Khmer
$⟨ð⟩$ is sometimes used in Khmer romanization to represent ឍ thô.

Icelandic


In Icelandic, $⟨d⟩$, called "eð", represents an alveolar non-sibilant fricative, voiced intervocalically and word-finally, and voiceless  otherwise, which form one phoneme,. Generally, is represented by  thorn $⟨Ð⟩$ at the beginning of words and by $⟨ð⟩$ elsewhere. The $⟨Þ⟩$ in the name of the letter is devoiced in the nominative and accusative cases:. In the Icelandic alphabet, $⟨ð⟩$ follows $⟨ð⟩$.

Norwegian
In Olav Jakobsen Høyem's version of Nynorsk based on Trøndersk, $⟨ð⟩$ was always silent, and was introduced for etymological reasons.

Old English
In Old English, $⟨d⟩$ (called ðæt) was used interchangeably with $⟨ð⟩$ to represent the Old English dental fricative phoneme or its allophone, which exist in modern English phonology as the voiceless and voiced dental fricatives both now spelled $⟨ð⟩$.

Unlike the runic letter $⟨þ⟩$, $⟨th⟩$ is a modified Roman letter. Neither $⟨þ⟩$ nor $⟨ð⟩$ was found in the earliest records of Old English. A study of Mercian royal diplomas found that $⟨ð⟩$ (along with $⟨þ⟩$) began to emerge in the early 8th century, with $⟨ð⟩$ becoming strongly preferred by the 780s. Another source indicates that the letter is "derived from Irish writing".

Under the reign of King Alfred the Great, $⟨đ⟩$ grew greatly in popularity and started to overtake $⟨ð⟩$, and completely overtook it by Middle English. However, $⟨þ⟩$ in turn died out by Early Modern English, mostly due to the rise of the printing press, and was replaced by the digraph th.

Welsh
$⟨ð⟩$ has also been used by some in written Welsh to represent, which is normally represented as dd.

Phonetic transcription

 * (U+00F0) represents a voiced dental fricative in the International Phonetic Alphabet.
 * (U+1D9E) is used in phonetic transcription.
 * ᴆ (U+1D06) is used in the Uralic Phonetic Alphabet.

Computer encoding
Upper and lower case forms of eth have Unicode encodings:

These Unicode codepoints were inherited from ISO/IEC 8859-1 ("ISO Latin-1") encoding.

Modern uses

 * A capital eth is used as the currency symbol for Dogecoin, a cryptocurrency.