ultracold

adjective

ul·​tra·​cold ˌəl-trə-ˈkōld How to pronounce ultracold (audio)
Synonyms of ultracoldnext
: having a very low temperature : extremely or extraordinarily cold
ultracold liquid nitrogen
ultracold temperatures

Examples of ultracold 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.
There, the trio tinkered with ultracold electronics to show that unruly quantum effects could be made macroscopic and controlled. — Dan Garisto, Scientific American, 7 Oct. 2025 The number of ultracold atoms in the resulting Bose-Einstein condensate was measured and fed back to the player as a score. — IEEE Spectrum, 22 Oct. 2019 Its infrared sensors, its ultracold location in space, and its sunshield — which blocks the light of the sun, moon and Earth — are uniquely suited to resolve the first galaxies and their stars. — Rebecca Boyle, Quanta Magazine, 9 Oct. 2024 The biggest challenge is that the property was observed at ultracold temperatures of about 60 kelvins (-351 °F/-213 °C). — Abhimanyu Ghoshal, New Atlas, 13 June 2025 See All Example Sentences for ultracold

Word History

First Known Use

1861, in the meaning defined above

Time Traveler
The first known use of ultracold was in 1861

Rhymes for ultracold

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Browse Nearby Words

ultraclean
ultracold
ultra-commercial
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Cite this Entry

“Ultracold.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ultracold. Accessed 10 Jul. 2026.

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