asteroid

[ as-tuh-roid ]

/ ˈæs təˌrɔɪd /

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See synonyms for asteroid on Thesaurus.com

noun

Astronomy. any of millions of small celestial objects revolving around the sun, often irregularly shaped and having a great range in size, from as small as 6 feet (2 meters) across to about 620 miles (998 kilometers) across: the vast majority of known asteroids exist within the asteroid belt. See also small solar system body.

Zoology. a starfish; an asteroidean.

adjective

starlike.

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Origin of asteroid

First recorded in 1795–1805; from Greek asteroeidḗs “starry, starlike”; see star, -oid

OTHER WORDS FROM asteroid

as·ter·oi·dal, adjectivein·ter·as·ter·oi·dal, adjective

Words nearby asteroid

asteriated, asterisk, asterism, astern, asternal, asteroid, asteroid belt, Asteroidea, asteroidean, Asteropaeus, aster yellows

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use asteroid in a sentence

Perhaps, Carr and a few others have imagined, LUCA was the descendent of microbial Martian invaders traveling by asteroid.
Your ancestors might have been Martians|Charlie Wood|February 12, 2021|Popular-Science
The analogs in the solar system are all asteroid-sized bodies much less massive than Earth.
Two exoplanet families redefine what planetary systems can look like|Lisa Grossman|February 5, 2021|Science News
As he sorts through it, Genge could conceivably come across a speck of 6626 Mattgenge, an 8-kilometer-wide asteroid near Mars named in his honor for his contributions to the study of cosmic dust.
What Dust From Space Tells Us About Ourselves|Natalie Wolchover|February 4, 2021|Quanta Magazine
Although the company has struggled, Bezos has invested to the tune of $1 billion a year in the company and rhapsodizes about a future in which humans live in massive habitats in orbit and mine asteroids.
Jeff Bezos stepping down as Amazon CEO, transitioning to executive chair role|Jay Greene, Tony Romm|February 4, 2021|Washington Post

NASA’s OSIRIS-REx mission successfully touched down on the asteroid Bennu and collected an overflowing amount of material to bring back to Earth.
We’re living in a golden age of sample return missions|Neel Patel|February 2, 2021|MIT Technology Review
What would it take to carry people to the Moon, or Mars, or an asteroid?
To Infinity and Beyond! NASA’s Orion Mission Blasts Off|Matthew R. Francis|December 4, 2014|DAILY BEAST
Thinking of longer journeys to Mars or an asteroid would require careful measurement of conditions.
To Infinity and Beyond! NASA’s Orion Mission Blasts Off|Matthew R. Francis|December 4, 2014|DAILY BEAST
His game lasts until his final ship has either collided with an asteroid or lost a shootout with an enemy saucer.
‘Asteroids’ & The Dawn of the Gamer Age|David Owen|November 29, 2014|DAILY BEAST
The Asteroid Belt in the Solar System has many such gaps, created by the gravity of the Sun and Jupiter.
The Most Stunning View Ever of Planets Being Born|Matthew R. Francis|November 9, 2014|DAILY BEAST
For the record, Deep Impact is about a comet, not an asteroid.
U.S.—Russia Tensions Nuke Plans For Real-Life ‘Armageddon’ Asteroid Defense|Asawin Suebsaeng|August 4, 2014|DAILY BEAST
According to Boyle, a non-luminous and non-reflecting asteroid has crashed into the earth's gravitational field.
Astounding Stories, May, 1931|Various
In the early afternoon they came to what must be the asteroid's northern pole.
The Devil's Asteroid|Manly Wade Wellman
It always landed on the plain where Parr had first set foot to the asteroid.
The Devil's Asteroid|Manly Wade Wellman
"They were inside this asteroid," decided Parr, half to himself.
The Devil's Asteroid|Manly Wade Wellman
"For getting away, for giving freedom to my only friends on this asteroid," said Parr.
The Devil's Asteroid|Manly Wade Wellman

British Dictionary definitions for asteroid

asteroid

/ (ˈæstəˌrɔɪd) /

noun

Also called: minor planet, planetoid any of numerous small celestial bodies that move around the sun mainly between the orbits of Mars and Jupiter. Their diameters range from 930 kilometres (Ceres) to less than one kilometre

Also called: asteroidean (ˌæstəˈrɔɪdɪən) any echinoderm of the class Asteroidea; a starfish

adjective Also: asteroidal (ˌæstəˈrɔɪdəl)

of, relating to, or belonging to the class Asteroidea

shaped like a star

Word Origin for asteroid

C19: from Greek asteroeidēs starlike, from astēr a star

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for asteroid

asteroid

[ ăs′tə-roid′ ]

Any of numerous small solar system bodies that orbit the Sun primarily in the asteroid belt, a region between the orbits of Mars and Jupiter. Asteroids are intermediate in size between planets and meteoroids with diameters that measure between approximately one hundred and several hundred kilometers. While more than 1,800 asteroids have been cataloged, and as many as a million or more smaller ones may exist, their total mass has been estimated to be less than three percent of the Moon's. Asteroids are thought to be left over from the early formation of the solar system, when planetesimals in a protoplanetary disk were scattered after coming under Jupiter's gravitational influence. The continuing collision of planetesimals that remained between Jupiter and Mars caused many of them to fragment, creating the asteroids that exist today. Also called minor planet planetoid

Cultural definitions for asteroid

asteroid

[ (as-tuh-royd) ]

A small planet that revolves around the sun. The largest asteroid is only about six hundred miles in diameter. (See asteroid belt.)

asteroid

Origin of asteroid

OTHER WORDS FROM asteroid

Words nearby asteroid

Words related to asteroid

How to use asteroid in a sentence

British Dictionary definitions for asteroid

Word Origin for asteroid

Scientific definitions for asteroid

Cultural definitions for asteroid