Try Our Apps


Words You've Been Using Wrong


[plan-i-ter-ee] /ˈplæn ɪˌtɛr i/
of, relating to, or resembling a planet or the planets.
wandering; erratic.
terrestrial; global.
Machinery. noting or pertaining to an epicyclic gear train in which a sun gear is linked to one or more planet gears also engaging with an encircling ring gear.
Machinery. a planetary gear train.
Origin of planetary
From the Latin word planētārius, dating back to 1585-95. See planet, -ary
Related forms
nonplanetary, adjective
Can be confused
planetary, plenary, plentiful, plenitude. Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
Cite This Source
Examples from the Web for planetary
Contemporary Examples
Historical Examples
  • You get in touch with planetary health services immediately!

    Pariah Planet Murray Leinster
  • The planetary president, Wilcox, is in alliance with the war party.

    The Martian Cabal Roman Frederick Starzl
  • The planetary rulers had taken no chances of tampering with their propaganda.

    The Martian Cabal Roman Frederick Starzl
  • I see sir, that you are most apt in the calculation of the planetary hours.

    The Memoires of Casanova, Complete Jacques Casanova de Seingalt
  • But there are hundreds of planetary bodies now known that were then not known.

    The Book of the Damned Charles Fort
British Dictionary definitions for planetary


/ˈplænɪtərɪ; -trɪ/
of or relating to a planet
mundane; terrestrial
wandering or erratic
(astrology) under the influence of one of the planets
(of a gear, esp an epicyclic gear) having an axis that rotates around that of another gear
(of an electron) having an orbit around the nucleus of an atom
noun (pl) -taries
a train of planetary gears
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
Cite This Source
Word Origin and History for planetary

1590s; see planet + -ary. Probably from Late Latin planetarius "pertaining to a planet or planets," but this is attested only as "an astrologer." Planetary nebula, so called for its shape, attested from 1785.

Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
planetary in Science
A large celestial body, smaller than a star but larger than an asteroid, that does not produce its own light but is illuminated by light from the star around which it revolves. In our solar system there are nine known planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. Because of Pluto's small size—about two-thirds the diameter of Earth's moon—and its unusual orbit, many astronomers believe it should actually be classed as a Kuiper belt object rather than a planet. A planetlike body with more than about ten times the mass of Jupiter would be considered a brown dwarf rather than a planet. See also extrasolar planet, inner planet, outer planet.

planetary adjective
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source

Word of the Day

Nearby words for planetary

Word Value for planetary

Scrabble Words With Friends