# -o-
## English
### Alternative forms

* -ö-

### Etymology 1

Adopted from Latin -o-, originating ultimately from Ancient Greek -ο- (-o-). In English, the connective is found from the Middle English period in direct borrowings from Latin. Direct formations of English terms with the connective, always combining Greek or Latin roots, appear from the 16th or 17th century. From the 18th century, the suffix becomes productive in compounds where the second element is English. From about 1800, formations on all sorts of stems become common.

#### Interfix

-o-
* A linking vowel inserted interconsonantally between two morphemes, to ease pronunciation, without contributing to the meaning. It frequently joins words or combining forms of Ancient Greek or Classical Latin origin in the classical compounds of New Latin and international scientific vocabulary, but it can also be used to join modern terms and even abbreviations, either formally or informally.
    extreme + -o- + -phile producing extremophileblog + -o- + -sphere producing blogospherespeed + -o- + meter producing speedometersadism + -o- + masochism producing sadomasochismsmell + -o- + vision producing smell-o-vision

##### Translations
#### See also

* -i-

### Etymology 2

Designated in the USAN guidelines for non-proprietary names of monoclonal antibodies.

#### Affix

-o-
* (pharmacology) a monoclonal antibody derived from a murine source

##### Related terms

* -mab is the base suffix common to all monoclonal antibodies. (See that entry for full paradigm.)

##### References

* USP Dictionary of USAN and International Drug Names, U.S. Pharmacopeia, 2000

### Further reading

* “-o-”, in OneLook Dictionary Search.
* “-o-”, in Merriam-Webster Online Dictionary, Springfield, Mass.: Merriam-Webster, 1996–present.
* “-o-”, in The American Heritage Dictionary of the English Language, 5th edition, Boston, Mass.: Houghton Mifflin Harcourt, 2016, →ISBN.
* “-o-” in TheFreeDictionary.com, Huntingdon Valley, Pa.: Farlex, Inc., 2003–2025.
* “-o-”, in OED Online ⁠, Oxford: Oxford University Press, launched 2000.
* John A. Simpson and Edmund S. C. Weiner, editors (1989), “-o, suffix.”, in The Oxford English Dictionary, 2nd edition, Oxford: Clarendon Press, →ISBN.

## Catalan
### Interfix

-o-
* -o- (forms compounds)

#### Derived terms
## Czech
### Etymology

Inherited from Old Czech -o-, from Proto-Slavic *-o-.

### Interfix

-o-
* forms compounds

#### Derived terms
## Dutch
### Interfix

-o-
* -o-

#### Derived terms
## French
### Pronunciation

* IPA: /o/

### Interfix

-o-
* -o-

#### Derived terms
## German
### Pronunciation

* Audio:(file)

### Interfix

-o-
* -o-

#### Derived terms
## Hungarian
### Pronunciation

* IPA: [o]

### Interfix

-o-
* A suffix-initial vowel (or linking vowel) inserted interconsonantally between the word stem and the suffix, to ease pronunciation, without contributing to the meaning.
    ‎kor (“age”) + ‎-o- + -k → ‎korok (“ages”)

### See also

* -a-
* -á-
* -e-
* -ö-

## Kashubian
### Etymology

Inherited from Proto-Slavic *-o-. Compare Slovincian -ô-

### Pronunciation

* IPA: /-ɔ-/

### Interfix

-o-
* used to link two words in some compounds; -o-

#### Derived terms
## Latin
### Etymology

Adopted from the thematic vowel in Ancient Greek -ο- (-o-), often used to form nominal compounds. In Ancient Greek, the connective suffix originates in compounds where the first member is thematic, such as δημοκρατία (dēmokratía), but was extended by analogy to other stems, such as μητρόπολις (mētrópolis). The suffix was borrowed as a connective into Latin, mainly in compounds of Greek origin.
The suffix becomes productive and forms new compounds in learned humanist Latin, from the Renaissance. The connective is especially productive in connecting ethnonyms or geographical terms; genuine Greek stems include Gallo-, and Syro-, but most are of medieval or modern origin, productive from the 15th century, such as Anglo-, Graeco- or Latino-.

### Interfix

-o-
* (post-classical Latin) Suffix forming nominal compounds (such as anglosaxonicus (“Anglo-Saxon”), from Anglus (“Angle, English”) and saxonicus (“Saxon”)).

#### Derived terms
## Old Polish
### Etymology

Inherited from Proto-Slavic *-o-.

### Pronunciation

* IPA: (10th–15th CE) /ɔ/
* IPA: (15th CE) /ɔ/

### Interfix

-o-
* used in compound words

#### Descendants

* Polish: -o-
* Silesian: -o-

## Polish
### Etymology

Inherited from Old Polish -o-.

### Pronunciation

* IPA: /ɔ/
* Audio:(file)
* Rhymes: -ɔ
* Syllabification: [please specify syllabification manually]
* Homophones: o, o-, -o

### Interfix

-o-
* used in compound words
    ‎deszcz + ‎-o- + ‎mierzyć → ‎deszczomierz

#### See also

* -i-, -u-, -y-

## Romanian
### Interfix

-o-
* -o-

#### Derived terms
## Serbo-Croatian
### Etymology

Inherited from Proto-Slavic *-o-

### Interfix

-o- (Cyrillic spelling -о-)
* Interfix used for forming nominal compounds.
    kiš + -o- + -bran → kȉšobrān

#### Derived terms
## Slovak
### Etymology

Inherited from Proto-Slavic *-o-

### Interfix

-o-
* Used to form compounds.

#### Derived terms
## Slovene
### Etymology

Inherited from Proto-Slavic *-o-

### Interfix

-o-
* Used to form compounds.

#### Derived terms
## Swahili
### Infix

-o-
* infixed form of -o (“wa class$_{(II)}$, m class$_{(III)}$, and u class$_{(XI)}$ relative marker”)

#### See also

For a full table including first and second person, see Appendix:Swahili personal pronouns

## Swedish
### Etymology

From Old Swedish -u, -o, from the Old Swedish genitive form of Germanic feminine ōn-stems.
Alternates with -u- according to Old Swedish rules of syllable weight, where -o was used after heavy syllables and -u after light.

### Interfix

-o-
* Genitival interfix used to link elements in some compounds.

#### Usage notes

* Used as interfix in compounds with certain old weak feminines ending in -a. Some common ones are hälsa (“health”), e.g. hälsocentral (“health center”); kvinna (“woman”), e.g. kvinnoorganisation (“women's organisation”); känsla (“feeling”), e.g. känsloliv (“emotional life”); vecka (“week”), e.g. veckodag (“day of the week”); vila (“rest”), e.g. vilopuls (“resting heart rate”); lära (“teaching, theory”), e.g. läromedel (“teaching aids”); föda (“food, diet”), e.g. födoämne (“foodstuff”); människa (“human”), e.g. människovärde (“human dignity”); saga (“tale”), e.g. sagobok (“storybook”), etc.
* Alternates with a zero interfix (vowel deletion) in some words, cf. kyrkogård (“churchyard”), but kyrktorn (“church tower”); kronofogde (“enforcement officer”), but kronblad (“petal”).
* The interfix was formerly mostly confined to the written literary language, whereas the spoken colloquial language preferred compounds with no -o- or with -e- in some dialects, but forms with -o- are now common in the spoken language, and formerly colloquial pronunciations such as körrgård for kyrkogård are today less common.

#### Derived terms
### See also

* -u-
* -s-
* -a-
* -e-

### References

* Teleman, Ulf; Hellberg, Staffan; Andersson, Erik & Holm, Lisa (1999). Svenska akademiens grammatik 2 Ord. Stockholm: Svenska akad.
* Wessén, Elias (1958). Svensk språkhistoria. 2, Ordbildningslära. 3. ed. Stockholm: Almqvist & Wiksell

## Upper Sorbian
### Etymology

Inherited from Proto-Slavic *-o-.

### Pronunciation

* IPA: /ˈɔ/
* Syllabification: -o-

### Interfix

-o-
* used in compound words
    ‎horni + ‎-o- + ‎serbšćina → ‎hornjoserbšćina