Also called minor planet. Astronomy. any of the thousands of small bodies of from 480 miles (775 km) to less than one mile (1.6 km) in diameter that revolve about the sun in orbits lying mostly between those of Mars and Jupiter.
Zoology. an asteroidean; a starfish.
Origin of asteroid
Related formsas·ter·oi·dal, adjectivein·ter·as·ter·oi·dal, adjective
First recorded in 1795–1805, asteroid
is from the Greek
starry, starlike. See asterisk
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Related Words for asteroidsphere
Examples from the Web for asteroid
Contemporary Examples of asteroid
What would it take to carry people to the Moon, or Mars, or an asteroid?
Thinking of longer journeys to Mars or an asteroid would require careful measurement of conditions.
His game lasts until his final ship has either collided with an asteroid or lost a shootout with an enemy saucer.
The Asteroid Belt in the Solar System has many such gaps, created by the gravity of the Sun and Jupiter.
For the record, Deep Impact is about a comet, not an asteroid.
Historical Examples of asteroid
British Dictionary definitions for asteroid
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
Word Origin and History for asteroid
1802, coined probably by German-born English astronomer William Herschel (1738-1822) from Greek asteroeides "star-like," from aster "star" (see astro-) + -eidos "form, shape" (see -oid).
Online Etymology Dictionary, © 2010 Douglas Harper
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
The American Heritage® Science Dictionary
Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.