dark matter

noun

: nonluminous matter not yet directly detected by astronomers that is hypothesized to exist to account for various observed gravitational effects

Examples of dark matter in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The thick layer of rock shields it from cosmic rays, while a water tank and outer detectors help block or identify other particles that could mimic a dark matter signal. — Neetika Walter, Interesting Engineering, 1 Sep. 2026 Astronomers are very excited about Roman, for it's expected to discover thousands of new exoplanets and shed light on mysterious dark energy and dark matter, among other accomplishments. — Mike Wall, Space.com, 31 Aug. 2026 There, situated 750,000 miles beyond the moon, Roman will begin its science mission to study dark energy, dark matter and exoplanets. — Lee Billings, Scientific American, 31 Aug. 2026 Its five-year mission is to study dark matter and hunt for habitable worlds outside our solar system. — Eric Lagatta, USA Today, 31 Aug. 2026 See All Example Sentences for dark matter

Word History

First Known Use

1933, in the meaning defined above

Time Traveler
The first known use of dark matter was in 1933

Rhymes for dark matter

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Browse Nearby Words

darkly
dark matter
dark meat
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Cite this Entry

“Dark matter.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/dark%20matter. Accessed 5 Sep. 2026.

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More from Merriam-Webster on dark matter

Britannica.com: Encyclopedia article about dark matter

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