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[plan-i-toid] /ˈplæn ɪˌtɔɪd/
noun, Astronomy.
an asteroid.
Origin of planetoid
First recorded in 1795-1805; planet + -oid
Related forms
planetoidal, adjective Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2017.
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Examples from the Web for planetoid
Contemporary Examples
Historical Examples
  • Should he stay with the planetoid to its end, and thus perforce return to Eddore with no material evidence whatever?

    Triplanetary Edward Elmer Smith
  • The crops continued to grow on the tamed black dirt of the planetoid.

    Beside Still Waters Robert Sheckley
  • The tugs would be able to find the planetoid by following the beeps.

    Anchorite Randall Garrett
  • We are nearing a planetoid, or, as some call them, an asteroid!

    Through Space to Mars Roy Rockwood
  • With a ship like that, you could run through a planetoid without hurting the hull.

    Islands of Space John W Campbell
  • He knew he must return to the planetoid and somehow kill the opponent.

    The Dueling Machine Benjamin William Bova
  • They allege that the planetoid is a security risk, in that it could be used for remote-control bombing of any of their planets.

    Mr. President Stephen Arr
  • The rocket roared to life and Odal was hurtled free of the boulder, shot uncontrolled completely off the planetoid.

    The Dueling Machine Benjamin William Bova
  • Roger had been sublimely confident that he could detect the use, anywhere in or around his planetoid, of ultra-wave.

    Triplanetary Edward Elmer Smith
British Dictionary definitions for planetoid


another name for asteroid (sense 1)
Derived Forms
planetoidal, adjective
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
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planetoid in Science
See asteroid.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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