"Õ" (uppercase), or "õ" (lowercase) is a composition of the Latin letter O with the diacritic mark tilde.
The HTML entity is Õ for Õ and õ for õ. 詳細

In Estonian, Õ is the 27th letter of the alphabet (between W and Ä), and it represents a vowel characteristic of Estonian, the unrounded … 詳細

In Hungarian, Õ only appears when a typeface (font set) does not contain a proper "ő" letter, which is an "o" with a double acute diacritic. … 詳細

In the Vietnamese language, the symbol Õ stands for the sound [ɔ] with creaky voice (rising tone with a glottal break followed by a continuation of the rising tone). Vietnamese also … 詳細

For Romagnol language, õ is used in some proposed orthographies to represent [õː], e.g. savõ [saˈvõː] "soap". To this day a unified standardization has not been established. 詳細

In the Guarani language, Õ is the 22nd letter and fourth nasal vowel of the alphabet, similar to the Spanish "o", but with a 詳細

In Samogitian the letter Õ represents, as in Estonian, the unrounded back vowel /ɤ/ which is unique to Samogitian and is not found in Standard … 詳細