plan·​e·​tary | \ ˈpla-nə-ˌter-ē How to pronounce planetary (audio) \

Definition of planetary

1a : of, relating to, being, or resembling a planet
c : having a motion like that of a planet planetary electrons
d : immense the scope of this project has reached planetary proportions
2a : of, relating to, or belonging to the earth : terrestrial
b : global, worldwide planetary politics
3 : having or consisting of an epicyclic train of gear wheels

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Examples of planetary in a Sentence

a positively planetary new shopping development

Recent Examples on the Web

As the day approaches when extra-planetary travel becomes more accessible (at least, initially, to billionaire space tourists), researchers are developing tools to ease the transition to weightless living. Leigh Kamping-carder, WSJ, "How a Robotic Tail Could Help Future Space Travelers," 5 Apr. 2019 Meanwhile, the Mars Reconnaissance Orbiter will record the entry, descent, and landing of InSight in real time, but because of planetary dynamics, that spacecraft won't relay that information back to Earth for about three hours. Eric Berger, Ars Technica, "Here’s how NASA will attempt to land on the Red Planet Monday," 26 Nov. 2018 Committees will soon begin working on the next one for planetary endeavors, which will cover 2023 to 2032. Meghan Bartels,, "What Would It Take to Land on Mercury? It's Time to Find Out, Scientists Say," 30 Aug. 2018 During the first half of the month, the planets Mercury and Saturn will create a challenging planetary pair for sky-watchers. National Geographic, "Blue Moon Eclipse and More Can't-Miss Sky Events in January," 1 Jan. 2018 Those first images from Opportunity inspired me to become a planetary scientist. Robert Lee Hotz, WSJ, "NASA Calls It Quits for Opportunity Mars Rover After 15-Year Mission," 13 Feb. 2019 After all, no one can say for certain exactly how much human activity contributes to planetary warming, or how effective any given intervention would be at stopping it. Eric Levitz, Daily Intelligencer, "The EPA Is Instructing Its Staffers to Cast Doubt on Climate Science," 28 Mar. 2018 The other chapters are topical and somewhat scientific, covering in sequence the tools for telling time; the mode and tempo of planetary processes; the longue durée of earth history; the role of geology in climate change. Robert M. Thorson, WSJ, "‘Timefulness’ Review: Thinking in Eons," 30 Dec. 2018 There are these planetary probes, there’s the Hubble Telescope, there’s a ... Eric Johnson, Recode, "Full Q&A: Tesla and SpaceX CEO Elon Musk on Recode Decode," 2 Nov. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'planetary.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of planetary

1607, in the meaning defined at sense 1a

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Statistics for planetary

Last Updated

11 Apr 2019

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Time Traveler for planetary

The first known use of planetary was in 1607

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More Definitions for planetary



English Language Learners Definition of planetary

technical : of or relating to planets


plan·​e·​tary | \ ˈpla-nə-ˌter-ē How to pronounce planetary (audio) \

Kids Definition of planetary

1 : of or relating to a planet
2 : having a motion like that of a planet

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Comments on planetary

What made you want to look up planetary? Please tell us where you read or heard it (including the quote, if possible).


an act or instance of returning to life

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