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interplanetary

American  
[in-ter-plan-i-ter-ee] / ˌɪn tərˈplæn ɪˌtɛr i /

adjective

  1. being or occurring between the planets or between a planet and the sun.

interplanetary British  
/ ˌɪntəˈplænɪtərɪ, -trɪ /

adjective

  1. of, relating to, or existing between planets

"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

Etymology

Origin of interplanetary

First recorded in 1685–95; inter- + planetary

Vocabulary lists containing interplanetary

Lesson 2

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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.

Genly Ai’s mission is to persuade the governments on Gethen to join a larger interplanetary coalition.

From The Wall Street Journal • Dec. 12, 2025

The fast solar wind -- a supersonic stream of charged particles -- originates mainly in the Sun's polar coronal holes and fills most of the heliosphere, shaping conditions in interplanetary space.

From Science Daily • Oct. 14, 2025

Elio doesn’t do too much sulking before he’s beamed up to the Communiverse, an interplanetary take on the United Nations.

From Los Angeles Times • Jun. 18, 2025

Decades later and after several successful interplanetary missions, Isro’s budget remains modest.

From BBC • Nov. 3, 2024

Velikovsky imagined the comet, after a complicated game of interplanetary billiards, to settle down into a stable, nearly circular orbit, becoming the planet Venus—which he claimed never existed before then.

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.