# asteroid
## English
### Pronunciation

* enPR: ăs'tə-roid", IPA: /ˈæst(ə)ɹɔɪd/
* Audio (US):(file)
* Homophone: astroid (one pronunciation)

### Etymology 1

From aster +‎ -oid, lit. "star-like". Coined by William Herschel.

#### Noun

asteroid (plural asteroids)
* (astronomy) A naturally occurring solid object, which is smaller than a planet and a dwarf planet, larger than a meteoroid and not a comet, that orbits a star and often has an irregular shape.
* (astronomy) In the Solar system, such a body that orbits within the orbit of Jupiter
** 2007, Hannu Karttunen et al., editors, Fundamental Astronomy, 5th edition, page 131:The orbital planes of asteroids, minor bodies that circle the Sun mainly between the orbits of Mars and Jupiter, are often more tilted ...

##### Usage notes

The term "asteroid" has never been precisely defined. It was coined for objects which looked like stars in a telescope but moved like planets. These were known from the asteroid belt between Mars and Jupiter, and were later found co-orbiting with Jupiter (Trojan asteroids) and within the orbit of Mars. They were naturally distinguished from comets, which did not look at all starlike. Starting in the 1970s, small non-cometary bodies were found outside the orbit of Jupiter, and usage became divided as to whether to call these "asteroids" as well. Some astronomers restrict the term "asteroid" to rocky or rocky-icy bodies with orbits up to Jupiter. They may retain the term planetoid for all small bodies, and thus tend to use it for icy or rocky-icy bodies beyond Jupiter, or may use dedicated words such as centaurs, Kuiper belt objects, transneptunian objects, etc. for the latter. Other astronomers use "asteroid" for all non-cometary bodies smaller than a planet, even large ones such as Sedna and (occasionally) Pluto. However, the distinction between asteroid and comet is an artificial one; many outer "asteroids" would become comets if they ventured nearer the Sun. The IAU terminology since 2006 has been small Solar System body for any body that orbits the Sun directly and whose shape is not dominated by gravity.

##### Derived terms

* Apohele asteroid
* asterite
* asteroidal
* asteroid belt
* asteroidlike
* Atira asteroid
* binary asteroid
* iceteroid
* interasteroid
* kuiperoid
* Vatira asteroid
* ꞌAylóꞌchaxnim asteroid

##### Related terms

* aster
* asterisk
* asterism
* minor planet

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

* astroid
* comet
* exoasteroid
* meteor
* meteorite
* planetoid

### Etymology 2

Borrowed from Ancient Greek ἀστεροειδής (asteroeidḗs), from ἀστήρ (astḗr, “star”) + εἶδος (eîdos, “form”). Analyzable as aster- +‎ -oid.

#### Noun

asteroid (plural asteroids)
* (zoology) Any member of the taxonomic class Asteroidea; a starfish.

### Further reading

* “asteroid”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.
* “asteroid”, in The Century Dictionary […], New York, N.Y.: The Century Co., 1911, →OCLC.

### Anagrams

* ideators

## Czech
### Pronunciation

* IPA: [ˈastɛroɪt]

### Noun

asteroid m inan
* asteroid

#### Related terms

* See astro-

#### See also

* planetka

### Further reading

* “asteroid”, in Kartotéka Novočeského lexikálního archivu (in Czech)
* “asteroid”, in Slovník spisovného jazyka českého (in Czech), 1960–1971, 1989
* “asteroid”, in Internetová jazyková příručka (in Czech)

## Estonian
### Etymology

(This etymology is missing or incomplete. Please add to it, or discuss it at the Etymology scriptorium.)

### Pronunciation

* IPA: /ɑsteˈroi̯d̥/, [ɑsteˈroi̯d̥], /ˈɑsteroi̯d̥/, [ˈɑsteˌroi̯d̥]

### Noun

asteroid (genitive asteroidi, partitive asteroidi)
* asteroid

#### Declension
### Further reading

* “asteroid”, in [EKSS] Eesti keele seletav sõnaraamat [Descriptive Dictionary of the Estonian Language] (in Estonian) (online version), Tallinn: Eesti Keele Sihtasutus (Estonian Language Foundation), 2009

## Indonesian
### Etymology

From English asteroid.

### Pronunciation

* IPA: [asteˈroɪt̚]
* Hyphenation: as‧té‧ro‧id

### Noun

astéroid (plural asteroid-asteroid)
* (astronomy) asteroid
    Synonym: planetoid

### Further reading

* “asteroid” in Kamus Besar Bahasa Indonesia, Jakarta: Agency for Language Development and Cultivation – Ministry of Education, Culture, Research, and Technology of the Republic of Indonesia, 2016.

## Romanian
### Etymology

Borrowed from French astéroïde.

### Noun

asteroid m (plural asteroizi)
* asteroid

#### Declension
### Further reading

* asteroid in DEX online—Dicționare ale limbii române (Dictionaries of the Romanian language)

## Serbo-Croatian
### Pronunciation

* IPA: /asterǒiːd/

### Noun

asteròīd m (Cyrillic spelling астеро̀ӣд)
* asteroid

#### Declension
### Further reading

* “asteroid”, in Hrvatski jezični portal [Croatian language portal] (in Serbo-Croatian), 2006–2025

## Slovene
### Pronunciation

* IPA: /astɛrɔíːt/

### Noun

asteroȋd m inan
* asteroid

#### Inflection
### Further reading

* “asteroid”, in Slovarji Inštituta za slovenski jezik Frana Ramovša ZRC SAZU, portal Fran
* “asteroid”, in Termania, Amebis
* See also the general references

## Swedish
### Pronunciation

* Rhymes: -iːd

### Noun

asteroid c
* asteroid

#### Declension

| | | nominative | genitive |
| singular | indefinite | asteroid | asteroids |
| singular | definite | asteroiden | asteroidens |
| plural | indefinite | asteroider | asteroiders |
| plural | definite | asteroiderna | asteroidernas |