◌̈

◌̈

1. (mathematics, physics) The second time-differential. E.g. x (position), ẋ (velocity), ẍ (acceleration).
2. (IPA) A centralized vowel.
3. (NAPA) A front rounded vowel (e.g. ü ö ɔ̈) or a back unrounded vowel (e.g. ï ë ɛ̈).
4. (Teuthonista) Greater rounding of a vowel.

   Diacritic may be doubled for more rounding: ⟨ë̈⟩.

5. (ISO 233) Used with the letter ⟨ẗ⟩ to transcribe Arabic ⟨ة⟩.
6. (actuarial notation) Used to indicate that the payments occur at the beginning of a period.

   ä_n̅| ― n-year annuity-due

The spacing character U+00A8 is retained for compatibility with pre-Unicode encodings. It is equivalent to ◌̈ docked to a space, U+0020 (i.e. ⟨ ̈ ⟩), and there is no need for it in modern typography except to refer to itself.

• ⸚

◌̈

1. (dated) Used to indicate that two identical vowels occur in separate morphemes and are pronounced separately: coöperate, reënter, reëstablish, noöne.
2. Used to indicate that the marked vowel is the nucleus of its own syllable: Boötes, Brontë, Chloë, Zoë, (dated) aëroplane, aërial.
3. Retained in foreign (mostly French) loan words where vowels are pronounced separately: naïve (or naive), Noël (or Noel), but also for umlaut in German Götterdämmerung, Führer.

This diacritic is called a diaeresis (or dieresis), trema, or – strictly speaking for German and similar orthographies – umlaut.

In all such cases apart from family names, usage is optional. For German loans, there is the additional option of replacing the umlaut with a digraph in e, e.g. Fuehrer.

⟨◌́⟩ is more commonly used to indicate that a final e is pronounced, e.g. animé, but in the case of a name like Chloe that might imply the wrong stress or vowel quality (e.g. spurious "kloh-AY" rather than "KLOH-ee").

◌̈

1. Used with the letter ⟨e⟩ to make ⟨ë⟩, which transcribes the sound [ə]

◌̈

1. A diacritical mark of the Greek script, called διαίρεσις (diaíresis, “division”) in Ancient Greek, and found on Ϊ/ϊ and Ϋ/ϋ. It is also known by the names διαλυτική (dialutikḗ, “severing”) or τρῆμα (trêma, “dots on a die”). It was used to indicate that the vowel letter ι (i) or υ (u) formed a separate syllable rather than a diphthong when written after another vowel letter.

• (Greek-script letters) Α α, Β β, Γ γ, Δ δ, Ε ε, Ζ ζ, Η η, Θ θ, Ι ι, Κ κ, Λ λ, Μ μ, Ν ν, Ξ ξ, Ο ο, Π π, Ρ ρ, Σ σ ς, Τ τ, Υ υ, Φ φ, Χ χ, Ψ ψ, Ω ω
• (non-Classical letters) Ϝ ϝ, Ͷ ͷ, Ͱ ͱ, Ϻ ϻ, Ϙ ϙ, Ͳ ͳ
• (punctuation) · ;
• (diacritics) ᾿ ῾ ◌́ ◌̀ ῀ ¨

◌̈

1. A diacritical mark of the Latin script, called trema (“diaeresis”) in Dutch, and found on Ä/ä, Ë/ë, Ï/ï, Ö/ö and Ü/ü.
2. A diacritical mark of the Latin script, called umlaut (“umlaut”) in Dutch, and found on Ä/ä, Ö/ö and Ü/ü.

The diaeresis is used to indicate that two vowels are to be pronounced separately as two syllables, rather than as a diphthong or single vowel. For example, geïnd (collected), reëel (realistic), zeeën (seas). In compound words, a hyphen - is used between the syllables instead. The same occurs when a word is hyphenated at the end of a line of print, e.g. ge-ind, re-eel, zee-en for the previous.

The umlaut is used only in words of German origin, such as föhn.

◌̈

1. tréma; when placed above a letter, indicates that the vowel letter should be pronounced separately from a vowel letter next to it.

◌̈

1. A diacritical mark of the Latin script, called Umlaut (“umlaut”) in German, and found on Ä/ä, Ö/ö and Ü/ü.
2. A diacritical mark of the Latin script, called Trema in German, and found on Ë/ë and Ï/ï.

◌̈

1. A diacritical mark of the Greek script, called διαλυτικά in Greek, and found on ί/ΐ/ϋ.

◌̈

1. A diacritical mark of the Latin script, called tréma (“trema”) in Hungarian, and found on Ö/ö and Ü/ü.

◌̈

1. A diacritical mark of the Latin script, called doî pónti or diêrexi (“two points” or “diaeresis”) in Ligurian, and found on Ö/ö.
   1. Used to denote stressed or unstressed /ɔː/

◌̈

1. (obsolete) A diacritical mark of the Latin script, called trema (“trema”) in Portuguese, and found on Ü/ü.

• Formerly used, in the letter u, formed ü, in the syllables qüe, qüi, güe and güi. In these syllables, the letter u without a trema would be silent; with the trema it would have the sound of the semivowel /w/.

◌̈

1. A diacritical mark of the Latin script in Romani, and found on Ä/ä, Ë/ë, Ï/ï, Ö/ö and Ü/ü.

• Marcel Courthiade (2009) “DECISION : "THE ROMANI ALPHABET"”, in Melinda Rézműves, editor, Morri angluni rromane ćhibǎqi evroputni lavustik = Első rromani nyelvű európai szótáram : cigány, magyar, angol, francia, spanyol, német, ukrán, román, horvát, szlovák, görög [My First European-Romani Dictionary: Romani, Hungarian, English, French, Spanish, German, Ukrainian, Romanian, Croatian, Slovak, Greek] (overall work in Hungarian and English), Budapest: Fővárosi Onkormányzat Cigány Ház--Romano Kher, →ISBN, page 499
• “Introduction 3. How to read Rromani”, in R.E.D-RROM‎, 2021 October 2 (last accessed)
• Yūsuke Sumi (2018) ニューエクスプレスプラス　ロマ（ジプシー）語 [New Express Plus Romani (Gypsy)] (in Japanese), Tokyo: Hakusuisha, published 2021, →ISBN, →OCLC, pages 16-17

◌̈

1. A diacritical mark of the Latin script, called diéresis (“diaeresis”) in Spanish, and found on Ü/ü. Indicate that the 'u' is pronounced between a 'c' or 'g' and a vowel 'e' or 'i', as in Malagüez.

◌̈

1. A diacritical mark of the Latin script, called didolnod (“separation mark”) in Welsh, and found on Ä/ä, Ë/ë, Ï/ï, Ö/ö, Ü/ü, Ẅ/ẅ and Ÿ/ÿ.