Asteroid
//ˈæst(ə)ɹɔɪd// noun
noun ·Moderate ·College level
Definitions
Noun
- 1 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.
- 2 Any member of the taxonomic class Asteroidea; a starfish.
- 3 any of numerous small celestial bodies composed of rock and metal that move around the sun (mainly between the orbits of Mars and Jupiter) wordnet
- 4 In the Solar system, such a body that orbits within the orbit of Jupiter
"The orbital planes of asteroids, minor bodies that circle the Sun mainly between the orbits of Mars and Jupiter, are often more tilted ..."
Adjective
- 1 shaped like a star wordnet
Example
More examples"The asteroid broke up into small pieces as it entered Earth's atmosphere."
Etymology
Etymology 1
From aster + -oid, lit. "star-like". Coined by William Herschel.
Etymology 2
Borrowed from Ancient Greek ἀστεροειδής (asteroeidḗs), from ἀστήρ (astḗr, “star”) + εἶδος (eîdos, “form”). Analyzable as aster- + -oid. Piecewise doublet of etymology 1. Compare also the botanical taxon Asteroideae.
Related phrases
More for "asteroid"
Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.