noun Astronomy.

an asteroid.

Origin of planetoid

First recorded in 1795–1805; planet + -oid
Related formsplan·et·oi·dal, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for planetoid

Contemporary Examples of planetoid

  • Your may-be ruler Mercury teams with loving Venus, Monday, squaring Neptune and Chiron, the planetoid of healing.

    The Daily Beast logo
    Horoscopes for June 5-11, 2011

    Starsky + Cox

    June 4, 2011

Historical Examples of planetoid

  • The crops continued to grow on the tamed black dirt of the planetoid.

    Beside Still Waters

    Robert Sheckley

  • I had every executive on the planetoid jumping before I was through.

    A Spaceship Named McGuire

    Gordon Randall Garrett

  • The next three levels have all been burned into the bowels of the planetoid.

    The Risk Profession

    Donald Edwin Westlake

  • Then he nudged the Nancy Bell sideways, pushing the bolt down into the planetoid.


    Randall Garrett

  • The tugs would be able to find the planetoid by following the beeps.


    Randall Garrett

British Dictionary definitions for planetoid



another name for asteroid (def. 1)
Derived Formsplanetoidal, 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

planetoid in Science



See asteroid.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.