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.
Understanding that relationship could reveal new clues about Earth's climate, the evolution of life, and the conditions that might make other planetary systems habitable.
From Science Daily ● Sep. 2, 2026
While completing his graduate work at Caltech, Berne developed a model that uses subtle variations in gravity to estimate the internal structure of a planetary body.
From Science Daily ● Aug. 30, 2026
They were worried about El Niño, a planetary dance of weather phenomena that starts with spiking heat in the Pacific and deals out drought and floods across continents.
From The Wall Street Journal ● Aug. 29, 2026
Turtle and Lorenz are seasoned hands in the planetary science world.
From Los Angeles Times ● Aug. 22, 2026
An emerging technical civilization, after exploring its home planetary system and developing interstellar spaceflight, would slowly and tentatively begin exploring the nearby stars.
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.
