Esh (majuscule: Ʃ, minuscule: ʃ) is a character used in phonology to represent the voiceless postalveolar fricative (English ⟨sh⟩, as in "ship").
In Unicode, these letters are encoded as U+01A9 Ʃ LATIN CAPITAL LETTER ESH and U+0283 ʃ LATIN SMALL LETTER ESH
Form, usage, and history
Its lowercase form ⟨ʃ⟩ is similar to an integral sign ⟨ ∫⟩ or a cursive long s ⟨ ſ ⟩, with a leftward hook at the bottom. In 1928, the Africa Alphabet borrowed the Greek letter sigma ⟨Ʃ⟩ for use as the uppercase form. The lowercase form was introduced by Isaac Pitman in his 1847 Phonotypic Alphabet to represent the voiceless postalveolar fricative (English sh). It is not common around African languages, but it is, in fact, used in some. For example, the Serer Latin alphabet uses its lowercase form for the [ʄ] consonant.
The International Phonetic Alphabet (IPA) uses U+0283 ʃ LATIN SMALL LETTER ESH to represent a voiceless palato-alveolar sibilant. Related obsolete IPA characters include U+01AA ƪ LATIN LETTER REVERSED ESH LOOP, U+0285 ʅ LATIN SMALL LETTER SQUAT REVERSED ESH, and U+0286 ʆ LATIN SMALL LETTER ESH WITH CURL.
U+AB4D ꭍ LATIN SMALL LETTER BASELINE ESH is used in the Teuthonista phonetic transcription system.
Variations of esh are used for phonetic transcriptions of other phonemes: ⟨ᶋ⟩, ⟨ᶘ⟩, ⟨ʃ⟩.
U+1DF0B 𝼋 LATIN SMALL LETTER ESH WITH DOUBLE BAR and U+1DF0C 𝼌 LATIN SMALL LETTER ESH WITH DOUBLE BAR AND CURL are used as click letters.