Õ

O with tilde
O with tilde
Õ õ
Ö ö
Usage
Writing system	Latin script
Type	alphabetic
Sound values	[õː]; [o]; [ɤ]; [õ]; [ɔ̀ŋ]; [ɘ];
In Unicode	U+00D5, U+00F5
History
Development	Oᷠ oᷠ Õ õ;
Descendants	Ỗ ỗ, Ỡ ỡ
Variations	Ö ö
	This article contains phonetic transcriptions in the International Phonetic Alphabet (IPA). For an introductory guide on IPA symbols, see Help:IPA. For the distinction between [ ], / / and ⟨ ⟩, see IPA § Brackets and transcription delimiters.

Õ (uppercase), or õ (lowercase) is a composition of the Latin letter O with the diacritic mark tilde.

Romagnol

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.

Silesian

In the Silesian language, õ represents a dialectal letter representing [o], [a], [aum], [oum], and appears as the 22nd letter of the Ślabikŏrzōwy Szrajbōnek, one of the major Silesian alphabets.

Estonian

In Estonian, Õ is the 27th letter of the alphabet (between W and Ä), and it represents a vowel characteristic of Estonian, the unrounded back vowel /ɤ/, which may be close-mid back, close back, or close-mid central.^[1] The vowel was previously written with the letter Ö, but in the early 19th century, Otto Wilhelm Masing adopted the letter Õ, ending the confusion between several homographs and clearly showing how to pronounce a word.

In informal writing, e.g., emails, instant messaging and when using foreign keyboard layouts where the letter Õ is not available, some Estonians use the characters O or 6 to approximate this letter.

In most parts of the island Saaremaa, Õ is pronounced the same as Ö.

Guaraní

In Guaraní, Õ is the 22nd letter and fourth nasal vowel of the alphabet, similar to the Portuguese "õ", but with somewhat less stressed nasalization.

Hungarian

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.

Samogitian

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 Lithuanian, this is a rather new innovation brought on by the ensuing efforts of standardising Samogitian, this letter alleviates the confusion between the two distinct pronunciations of the letter ė.

Portuguese

In the Portuguese language, the symbol Õ stands for a nasal close-mid back rounded vowel, also written [õ] in IPA. It is not considered an independent letter of the alphabet: the tilde is the standard diacritic for nasalization.

Vietnamese

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 has derived letters Ỗ/ỗ and Ỡ/ỡ.

Võro

In the Võro language, this letter is the 25th letter of the alphabet, pronounced as in Estonian.

Skolt Sami

In the Skolt Sami language, this letter is the 25th letter of the alphabet, pronounced as [ɘ].

Voko

In the Voko language, the letter Õ represents 'ɔ̀ŋ'.

Mathematical use

The symbol, pronounced soft-O, is used as a variant of big O notation to measure growth rate that ignores logarithmic factors.^[2] Thus, $f(n)\in {\tilde {O}}(g(n))$ is shorthand for $\exists k:f(n)\in O(g(n)\log ^{k}n)$ .^[2]

Computer encoding

Character information
Preview	Õ		õ
Unicode name	LATIN CAPITAL LETTER O WITH TILDE		LATIN SMALL LETTER O WITH TILDE
Encodings	decimal	hex	dec	hex
Unicode	213	U+00D5	245	U+00F5
UTF-8	195 149	C3 95	195 181	C3 B5
Numeric character reference	Õ	Õ	õ	õ
Named character reference	Õ		õ

References

↑ Asu, Eva Liina; Teras, Pire (2009). "Estonian". Journal of the International Phonetic Association. 39 (3): 367–372. doi:10.1017/s002510030999017x.
1 2 Cormen, Thomas H. (2009). Introduction to algorithms (Third ed.). Cambridge, Mass.: MIT Press. p. 63. ISBN 978-0-262-27083-0. OCLC 676697295.

[1] Asu, Eva Liina; Teras, Pire (2009). "Estonian". Journal of the International Phonetic Association. 39 (3): 367–372. doi:10.1017/s002510030999017x.

[:0-2] 1 2 Cormen, Thomas H. (2009). Introduction to algorithms (Third ed.). Cambridge, Mass.: MIT Press. p. 63. ISBN 978-0-262-27083-0. OCLC 676697295.

[1]

[2]