interstellar

American  

[in-ter-stel-er] / ˌɪn tərˈstɛl ər /

adjective

1. Astronomy. situated or occurring between the stars.

   interstellar dust.

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interstellar British  

/ ˌɪntəˈstɛlə /

adjective

1. conducted, or existing between two or more stars

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Etymology

Origin of interstellar

First recorded in 1620–30; inter- + stellar

Explanation

If something happens or is located in between stars, it's interstellar. If you dream of interstellar travel, you're imagining flying through space — and maybe meeting a few extraterrestrials along the way. The area inside a galaxy is often referred to by astronomers as interstellar space. In fact, the adjective interstellar is frequently used in a general way as a synonym for "outer space" or "between solar systems." So if an astronaut is planning an interstellar trip, she may be traveling in space, but she's not literally making a journey from one star to another. The roots of interstellar are inter-, "between," and the Latin stella, or "star."

Example Sentences

Here, siblings Mario and Luigi team with Princess Peach and Toad on an interstellar adventure and face off against the nefarious fire-breathing Bowser and his son.

From The Wall Street Journal • Mar. 29, 2026

"When we detect water -- or even its faint ultraviolet echo, OH -- from an interstellar comet, we're reading a note from another planetary system," said Dennis Bodewits, professor of physics at Auburn.

From Science Daily • Feb. 11, 2026

If you were starting today, going to the moon or anywhere beyond, and especially into interstellar space, would be a job for robots and, often, exclusively robots.

From The Wall Street Journal • Feb. 10, 2026

Under these carefully controlled conditions, the team studied how particles behave when exposed to radiation, closely matching what happens in real interstellar space.

From Science Daily • Jan. 21, 2026

If, on an interstellar voyage, you are not paying attention, you can find yourself drawn into it irrevocably, your body stretched unpleasantly into a long, thin thread.

From "Cosmos" by Carl Sagan