Esperanto

Noun

dierezo ‎(accusative singular dierezon, plural dierezoj, accusative plural dierezojn)

1. (orthography) dieresis, a diacritic mark ( ¨ ) placed over the second of two consecutive vowels to indicate that the second vowel is to be pronounced separately.

See also

• surdupunkto ‎(“the ¨ mark”)
• umlaŭto ‎(“an umlaut”)

Usage notes

Two dots over a vowel ( ¨ ) indicates a dieresis in some languages, and an umlaut in others. The diacritical mark itself is called surdupunkto.