Eth

Ð
Ð ð
Usage
Writing system	Latin script
Type	Alphabetic and logographic
Language of origin	Old English Old Norse
Phonetic usage	[ð] [θ] [ð̠] /ˈɛð/
Unicode codepoint	U+00D0, U+00F0
History
Development	Δ δ 𐌃 D d Ꝺ ꝺ Ð ð
Time period	~800 to present
Sisters	None
Transliteration equivalents	d
Other
Other letters commonly used with	th, dh
Writing direction	Left-to-Right
This article contains phonetic transcriptions in the International Phonetic Alphabet (IPA). For an introductory guide on IPA symbols, see Help:IPA. For the distinction between [ ], / / and ⟨ ⟩, see IPA § Brackets and transcription delimiters.

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

It is often transliterated as ⟨d⟩.

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

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

Unlike the runic letter ⟨þ⟩, ⟨ð⟩ is a modified Roman letter. Neither ⟨ð⟩ nor ⟨þ⟩ was found in the earliest records of Old English. A study of Mercian royal diplomas found that ⟨ð⟩ (along with ⟨đ⟩) 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, ⟨þ⟩ 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.

 

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

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

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

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

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

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

Upper and lower case forms of eth have Unicode encodings:

• U+00D0 Ð LATIN CAPITAL LETTER ETH (Ð)
• U+00F0 ð LATIN SMALL LETTER ETH (ð)

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

• The letter ⟨ð⟩ (written ${\displaystyle \partial }$ ) 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.

• African D – Variant of the Latin letter D used in African alphabets
• D
• D with stroke – Variant of the letter D, used in Sámi alphabets, Serbo-Croatian Latin alphabet, and Vietnamese
• Insular script – Medieval writing system common to Ireland and England
• T
• Thorn – Letter of Old English and some Scandinavian languages