The letter "û" is a character used in several languages, including French and Turkish. It is formed by adding a circumflex accent (^) over the letter "u." This accent can change the pronunciation of the letter, often indicating a longer or more rounded vowel sound. In French, "û" appears in words like "dû," which means "due" or "owed." The circumflex can also signify that a letter, often "s," was historically present in the word but is no longer written. In Turkish, "û" represents a distinct vowel sound, contributing to the language's unique phonetic structure.