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. This super-catchy and clear alphabet song also lets children hear the letter O sound and see each letter at the beginning of five simple words paired with colorful kid-friend images. o - Wiktionary, the free dictionary. Jump to content. Main menu. move to sidebarhide. Navigation. Main page. Community portal. Requested entries. Recent changes. Random entry. Help. Glossary. Contact us. Special pages. Search. Appearance. Donations. Create account. Log in. Personal tools. Donations. Create account. Log in. Contents. Accents placed on the letter O —such as Ó, Ò, Ô, Õ, and Ö —change pronunciation, meaning, or grammatical emphasis. Accented O has a unique sound, and its usage varies depending on the language and context. O definition: the fifteenth letter of the English alphabet, a vowel. See examples of O used in a sentence. O is used to mean zero, for example when you are telling someone a phone number, or mentioning a year such as 1908. O (minuscule: o) is the fifteenth letter and the fourth vowel letter of the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Ó (minuscule: ó), known as O-acute, is a Latin-script character composed of the letter O and an acute accent. It is found in the Czech, Dobrujan Tatar, Emilian-Romagnol, Faroese, Hungarian, Icelandic, Kashubian, Polish, Slovak, Karakalpak, and Sorbian languages. The letter O is the fifteenth letter in the English alphabet and is classified as a vowel. It has two primary sounds: the long O sound, which is like the /O/ in open, and the short O sound, which is like the /o/ in octopus. The Letter O Song by Have Fun Teaching is a great way to learn all about the Letter O. Get unlimited teaching resources: . Us.