O, the fourth vowel of the modern alphabet, corresponding to the Semitic ayin, which represented a breathing and not a vowel. The Semitic form may have derived from an earlier sign representing an eye., Ó, ó (o - acute) is a letter in the Czech, Dobrujan Tatar, Emilian-Romagnol, Faroese, Hungarian, Icelandic, Kashubian, Polish, Slovak, Karakalpak, and Sorbian languages. The symbol also appears in the Afrikaans, Catalan, Dutch, Irish, Nynorsk, Bokmål, Occitan, Portuguese, Spanish, Italian and Galician languages as a variant of the letter "o"., Learn how to type O with accent mark on Windows and Mac. Acute, grave, circumflex, tilde, and umlaut accents change O's pronunciation., ô (lexicography) A dictionary transcription for the THOUGHT vowel; also an orthographic o with a diacritic that marks it as having that value, as in the word "nor". Synonyms: ȯ, ö, O is used to mean zero, for example when you are telling someone a phone number, or mentioning a year such as 1908., .