diacritic
/ˌdaɪəˈkrɪtɪk/
noun
- A mark, such as an accent or cedilla, added to a letter to show a special pronunciation or stress.
- The acute accent is a common diacritic in French, as in the word 'café'.
- When learning German, you must pay attention to the umlaut, a diacritic that alters vowel sounds.
- In Spanish, the tilde is a diacritic that changes the sound of the letter 'n'.