Overdot - Overdot

Overdot

Language scripts or transcription schemes that use the dot above a letter as a diacritical mark:

• In Arabic romanization, ġ stands for the letter ghayin.
• Traditional Irish typography, where the dot denotes lenition, and is called a ponc séimhithe or buailte "dot of lenition": ḃ ċ ḋ ḟ ġ ṁ ṗ ṡ ṫ. Alternatively, lenition may be represented by a following letter h, thus: bh ch dh fh gh mh ph sh th. In Old Irish orthography, the dot was used only for ḟ ṡ, while the following h was used for ch ph th; lenition of other letters was not indicated. Later the two systems spread to the entire set of lenitable consonants and competed with each other. Eventually the standard practice was to use the dot when writing in Gaelic script and the following h when writing in antiqua. Thus ċ and ch represent the same phonetic element in Modern Irish.
• Lithuanian: ė is pronounced as, compared to ę, which is pronounced a lower (formerly nasalised), or e, pronounced .
• Maltese: ċ is used for a voiceless postalveolar affricate, ġ for a voiced postalveolar affricate, and ż for a voiced alveolar fricative.
• Old English: In modernized orthography, ċ is used for a voiceless postalveolar affricate /t͡ʃ/, ġ for a palatal approximant /j/ (probably a voiced palatal fricative /ʝ/ in the earliest texts)
• Polish: ż is used for a voiced retroflex fricative.
• The Sioux languages such as Lakota and Dakota sometimes use the dot above to indicate explosive stops.
• In Turkish, the dot above lowercase i and j (and uppercase İ) is not regarded as an independent diacritic but as an integral part of the letter. It is called a tittle.
• In the Rheinische Dokumenta phonetic writing system overdots denote a special pronunciation of r.

The overdot is also used in the Devanagari script, where it is called anusvara.

In mathematics and physics, when using Newton's notation the dot denotes the time derivative as in . However, Newton's notation is no longer standard; instead this would be written with a prime or using Leibniz's notation.