Œ

Overview

In Latin, the combination denotes a diphthong, pronounced [oi̯], that had a value similar to English oi as in coil. It was used in borrowings from Greek words having the diphthong OI (ΟΙ, οι). Both classical and modern practice is to write the letters separately, but the ligature was used in medieval and early modern writings, in part because œ was reduced to a simple vowel ([e]) in late Latin.

English

A number of words written with œ were borrowed into English from Latin, but the œ is now rarely written. In modern American English, the sound is usually written as e, so diarrhœa has become diarrhea, although there are some exceptions, such as phoenix. In modern British English, the spellings generally keep the o but remove the ligature (e.g. diarrhoea).

The œ, oe, or e is generally pronounced /iː/ in syllables with word stress, or /ɛ/ when unstressed.

Other Germanic languages

Œ is used in the modern scholarly orthography of Old West Norse, representing the long vowel /øː/, contrasting with ø, which represents the short vowel /ø/. Recently, however, it has been replaced with ǿ, as in mǿðr "mothers".

Œ is not used in German; loanwords using œ are generally rendered ö, e.g. Ösophagus. A common exception is the French word Œuvre and its compounds (e.g. Œuvreverzeichnis).

Like German, Danish doesn't use œ, but unlike German, Danish replaces œ or œu in loan words with ø, as in økonomi "economy" from Greek via Latin œconomia or bøf "beef" from French bœuf

French

In French, œ (called e dans l'o, which means e in the o (a mnemotechnic pun used first at school, sounding like (des) œufs dans l'eau, meaning eggs in water, sometimes o et e collés, literally o and e glued) is a true linguistic ligature, not just a typographic one (like the fi or fl ligatures), reflecting etymology. It is most prominent in the words mœurs (“mores”), cœur (“heart”), sœur (“sister”), œuf (“egg”), bœuf (“beef”, "steer"), œuvre (“work”) and œil (“eye”), in which the digraph œu, like eu, represents the sound [œ] (in other cases, like plurals œufs (“eggs”) and bœufs (“steers”), it stands for [ø]).

French also uses œ in direct borrowings from Latin and Greek. So, “cœliac” in French is cœliaque. In such cases, the œ is classically pronounced [e], or, sometimes, in modern pronunciation, [œ]. In some words, like phénix and économique, the etymological œ is changed to a more French é.

In French placenames of German origin (mostly in and around Alsace-Lorraine, historically Germanic-speaking areas that have changed hands between France and Germany a number of times), œ replaces German ö and is pronounced [œ]. Examples include Schœneck (Moselle), Kœtzingue (Haut-Rhin), and Hœrdt (Bas-Rhin).

In all cases, œ is alphabetized as oe, rather than as a separate letter.

When oe occurs in French without the ligature, it is pronounced /wa/, just like words spelt with oi. The most common words of this type are poêle (“stove”, “frying pan”) and moelleux (“soft”). If the oe is not to be pronounced thus, then a diaeresis, acute or grave accent needs to be added in order to indicate that the vowels should be pronounced separately. For example, Noël, poésie, poète. The exception to this rule is when a morpheme ending in o is joined to one beginning in e, as in électroencéphalogramme, or with the prefix co-, which is always pronounced /ko/ in hiatus with the following vowel, as in coefficient (“ratio”, “coefficient”).

International Phonetic Alphabet

The symbol [œ] is used in the International Phonetic Alphabet for the open-mid front rounded vowel. This sound resembles the "œu" in the French œuf or the "ö" in the German öffnen. These contrast with French feu and German schön, which have the close-mid front rounded vowel, [ø].

The small capital variant [ɶ] represents the open front rounded vowel.

Encodings

In Unicode, the characters are encoded at U+0152 Œ LATIN CAPITAL LIGATURE OE (HTML Œ · Œ) and U+0153 œ LATIN SMALL LIGATURE OE (HTML œ · œ). In ISO-8859-15, Œ is 0xBC and œ 0xBD. In Windows-1252, at positions 0x8C and 0x9C. In Mac-Roman, they are at positions 0xCE and 0xCF.

Œ and œ were omitted from ISO-8859-1 (as well as derived standards, such as IBM code page 850), which are still widespread in internet protocols and applications. Œ is the only character in modern French that is not included in ISO-8859-1, and this has led to it becoming replaced by 'oe' in many computer-assisted publications (including printed magazines and newspapers). This was due, in part, to the lack of available characters in the French ISO/IEC 646 version that was used earlier for computing. Another reason is that œ is absent from most French keyboards, and as a result, few people know how to input it.

The above-mentioned small capital of the International Phonetic Alphabet is encoded at U+0276 ɶ LATIN LETTER SMALL CAPITAL OE (HTML ɶ).

Inputting Œ and œ

On Microsoft Windows, Œ and œ can be entered using the Alt codes 0140 and 0156, i.e. by holding down the Alt key while typing the number 0140 for Œ and 0156 for œ respectively on the numeric keypad. In Microsoft Word, œ can additionally be entered using the keyboard shortcut Ctrl+⇧ Shift+& then O in quick succession. Moreover, Microsoft Word and some other word processors can also automatically correct French words like soeur to sœur, but in most other applications (e.g. an instant messenger, or a browser) the word will not be corrected.

Using Apple's macOS, starting from Mac OS X Lion, Œ and œ can be accessed by holding down O (⇧ Shift+O) or o (O) and clicking on Œ and œ respectively in the small menu that appears. Alternatively the Character Viewer can be used to enter special characters. Furthermore, using either the U.S., British, or Swiss keyboard layout, Œ and œ are accessed by pressing ⌥ Opt+⇧ Shift+Q and ⌥ Opt+Q respectively. The corresponding key combinations on the French keyboard are ⌥ Opt+⇧ Shift+O and ⌥ Opt+O, or ⌥ Opt+⇧ Shift+Ö and ⌥ Opt+Ö on the German keyboard.

On mobile devices running iOS, Android or Windows Mobile, œ and Œ are accessed by holding down O until a small menu is displayed.

With a Compose key the key combination for œ is Compose O E and Compose ⇧ Shift+O ⇧ Shift+E for Œ.

In Vim (text editor), use Ctrl+K ⇧ Shift+O ⇧ Shift+E in succession (or Ctrl+K O E for lower-case).

The LaTeX commands are oe and OE .