Diacritic
A
diacritic /daɪ.əˈkrɪtɨk/ – also
diacritical mark,
diacritical point,
diacritical sign from ancient Greek
διά and
κρίνω – is a glyph added to a letter, or basic glyph. The term derives from the Greek
διακριτικός.
Diacritic is primarily an adjective, though sometimes used as a noun, whereas
diacritical is only ever an adjective. Some diacritical marks, such as the acute and grave are often called
accents. Diacritical marks may appear above or below a letter, or in some other position such as within the letter or between two letters. The main use of diacritical marks in the Latin script is to change the sound-value of the letter to which they are added. Examples from English are the diaereses in
naïve and
Noël, which show that the vowel with the diaeresis mark is pronounced separately from the preceding vowel; the acute and grave accents, which can indicate that a final vowel is to be pronounced, as in
saké and poetic
breathèd, and the cedilla under the "c" in the borrowed French word
façade, which shows it is pronounced /s/ rather than /k/.