Латын әрпі: «Eth» тарихы мен қолданылуы

Letter of the Latin alphabet; used in Icelandic, Faroese, and Old English

Eth (/ɛ//ð/// edh, 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 , and later
It is often transliterated as
The lowercase version has been adopted to represent a voiced dental fricative in the International Phonetic Alphabet.

In Old English, (called ðæt) was used interchangeably with to represent the Old English dental fricative phoneme or its allophone , which exist in modern English phonology as the voiced and voiceless dental fricatives both now spelled
Unlike the runic letter , is a modified Roman letter. Neither nor was found in the earliest records of Old English. A study of Mercian royal diplomas found that (along with ) began to emerge in the early 8th century, with 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, grew greatly in popularity and started to overtake , and completely overtook it by Middle English. However, in turn died out by Early Modern English, mostly due to the rise of the printing press, and was replaced by the digraph th.

In Icelandic, , 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 at the beginning of words and by elsewhere. The in the name of the letter is devoiced in the nominative and accusative cases: In the Icelandic alphabet, follows .

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

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

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

is sometimes used in Khmer romanization to represent ឍ .

(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.

The letter (written ) is sometimes used in mathematics and engineering textbooks, as a symbol for a spin weighted partial derivative. This operator gives rise to spin weighted spherical harmonics. A capital eth is used as the currency symbol for Dogecoin, a cryptocurrency.