interplanetary

adjective

in·​ter·​plan·​e·​tary ˌin-tər-ˈpla-nə-ˌter-ē How to pronounce interplanetary (audio)
: existing, carried on, or operating between planets
interplanetary dust
an interplanetary flight
interplanetary spacecraft

Examples of interplanetary in a Sentence

Recent Examples on the Web
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To investigate this, a set of 24 interplanetary type III bursts recorded by Parker Solar Probe over a one-week period was analyzed. Bojan Stojkovski, Interesting Engineering, 3 May 2026 These matters only scratch the surface of the problems any interplanetary spacefarers will face. Phil Plait, Scientific American, 1 May 2026 Michael agreed that pressure-testing our justifications for interplanetary travel would be a good use of our downtime. Elena Saavedra Buckley, Harpers Magazine, 21 Apr. 2026 According to EarthSky, the zodiacal light is sunlight reflecting off a vast cloud of interplanetary dust that lines the same path as the zodiac constellations. Valerie Mesa, PEOPLE, 17 Apr. 2026 See All Example Sentences for interplanetary

Word History

First Known Use

1691, in the meaning defined above

Time Traveler
The first known use of interplanetary was in 1691

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Cite this Entry

“Interplanetary.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/interplanetary. Accessed 20 May. 2026.

Kids Definition

interplanetary

adjective
in·​ter·​plan·​e·​tary
ˌint-ər-ˈplan-ə-ˌter-ē
: between planets
interplanetary space
interplanetary travel

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