O

Latin alphabet Aa Bb Cc Dd Ee Ff Gg Hh Ii Jj Kk Ll Mm Nn Oo Pp Qq Rr Ss Tt Uu Vv Ww Xx Yy Zz

O is the fifteenth letter of the Latin alphabet. Its name in English is o, plural o's or oes.

History

The letter was derived from the Semitic 'Ajin (eye) which represented a consonant, probably the pharyngeal consonant (IPA ʕ) similar to the Arabic letter ع called 'Ajn', but in Greek (Omicron), Etruscan and Latin it came to be used for the vowel /o/.

Usage

O is most commonly associated with the oʊ. In English, though, O has a short value which maps to ɒ (ɑ in parts of North America), while the long value tends to a diphthong of /o/ and ʊ. Common digraphs include OO (inconsistently with the sound ʊ or /u/), OI (usually a diphthong of ɔ and ɪ), as well as OA, OE, and OU with a variety of pronunciations depending on context.

Other languages use O for various values, usually back vowels which are at least partly open. Derived letters such as Ö and Ø have been created by some languages to distinguish values that were not present in Latin and Greek, particularly rounded front vowels.

In the International Phonetic Alphabet, [o] represents the close-mid back rounded vowel.

Alternative representations

Oscar represents the letter O in the NATO phonetic alphabet.

In international Morse code the letter O is DahDahDah: - - -

In Braille the letter O is represented as ⠕ (in Unicode), the dot pattern:

X.
.X
X.

Computing

In Unicode the capital O is codepoint U+004F and the lowercase o is U+006F.

The ASCII code for capital O is 79 and for lowercase o is 111; or in binary 01001111 and 01101111, correspondingly.

The EBCDIC code for capital O is 214 and for lowercase o is 150.

The numeric character references in HTML and XML are "O" and "o" for upper and lower case respectively.

Distinguishing O from zero

see 0 (number)#Distinguishing_zero_from_O

Meanings for O

O is a word in English, used as an interjection to indicate the vocative case, as in "O ye of little faith!"

In medicine, O (also, O+ or O-) is one of the human blood types.

In chemistry, O stands for oxygen.

In Normandy, O is a well-known and picturesque château. See Château d'O.

O is also a symbol for a hug, as in love notes. (See Hugs and Kisses.)

O is also the nickname of a magazine founded by Oprah Winfrey, more formally called O, The Oprah Magazine.

O may refer to the 2002 album by Damien Rice, see O (album).

O is also a film, see O (film).

O is a family name in Japanese; see O (name).

Story of O is a French erotic novel.

In economics, O is usually used to represent output.

In Windows, Ctrl-O, and Mac OS, Command-O, opens a file.

"O" is the name of a production show by Cirque du Soleil at the Bellagio (hotel and casino) in Las Vegas.

Big O notation is, in mathematics and computer science, used to describe the asymptotic behavior of a function or algorithm.

In mathematics, the orthogonal groups are designated by it.

o for ordentlich in German, meaning "of order". This was a title given to Austrian university professors of tenure status that are also research heads in their department. It was abolished in 1997, however, those who received it prior to to its abandonment are allowed to continue using it. The "o" is placed before the rest of the professor's title.

"O" was a minor character in the Transformers comics.

See also