planetary
Americanadjective
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of or relating to a planet
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mundane; terrestrial
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wandering or erratic
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astrology under the influence of one of the planets
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(of a gear, esp an epicyclic gear) having an axis that rotates around that of another gear
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(of an electron) having an orbit around the nucleus of an atom
noun
Other Word Forms
Etymology
Origin of planetary
From the Latin word planētārius, dating back to 1585–95. See planet, -ary
Explanation
The adjective planetary has to do with any astronomical body that revolves around a star — including the earth. Rather than a circle, planetary motion takes us in an elliptical shape around the sun. In science, planetary usually describes the attributes or motion of planets. It's also used for anything that behaves in a similar way, like planetary electrons, which revolve around their atomic nucleus as if they were tiny planets. You can also talk about things that affect our entire planet using this word: "She worries a lot about the planetary effects of climate change."
Vocabulary lists containing planetary
myPerspectives 7.2
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-ary
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
"We are trying to protect science and our investment in space," said Silvio Sinibaldi, the planetary protection officer at the European Space Agency and senior author of the study.
From Science Daily ● Jul. 13, 2026
The study was published in Journal of Geophysical Research: Planets, an AGU journal focused on planetary science.
From Science Daily ● Jul. 13, 2026
The findings provide some of the first direct evidence that salt clouds can exist in the atmosphere of a cold planetary object, confirming a prediction scientists first made more than 15 years ago.
From Science Daily ● Jun. 28, 2026
The discovery, described in the journal Earth and Planetary Science Letters, points to a type of planetary evolution unlike anything previously recognized.
From Science Daily ● Jun. 23, 2026
There may be a hundred billion planetary systems in the Galaxy awaiting exploration.
From "Cosmos" by Carl Sagan
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
