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

Each interstellar comet discovered so far has revealed something different about chemistry in other planetary systems.

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

"We saw that the glycine molecules started reacting with each other to form peptides and water. This indicates that the same process occurs in interstellar space," Alfred Thomas Hopkinson says.

From Science Daily • Jan. 21, 2026

The red star on the album’s cover was the symbol of the Solar Federation, the oppressive interstellar society in the story.

From "Ready Player One: A Novel" by Ernest Cline