absolute zero

noun

: a theoretical temperature characterized by complete absence of heat and motion and equivalent to exactly −273.15°C or −459.67°F

Examples of absolute zero in a Sentence

Recent Examples on the Web
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The wave nature of an atom shows itself only when the atom is barely moving, which only happens when it is cooled down to nearly absolute zero. Jacek Krywko, ArsTechnica, 11 Sep. 2026 Each of them features a superconducting film that’s cooled to a fraction of a degree above absolute zero. Georgina Jedikovska, Interesting Engineering, 11 Sep. 2026 That proximity should allow Chang’e 7 to prospect for water ice trapped in smaller depressions near Shackleton that, because of the moon’s tilt, never see sunlight and have temperatures just a few dozen degrees above absolute zero. Jonathan O'Callaghan, Scientific American, 20 Aug. 2026 Everything above absolute zero emits thermal radiation, and any temperature difference between object and surroundings produces a heat signature that is invisible to our eyes but perfectly legible to the right sensor. New Atlas, 29 July 2026 See All Example Sentences for absolute zero

Word History

First Known Use

1798, in the meaning defined above

Time Traveler
The first known use of absolute zero was in 1798

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Cite this Entry

“Absolute zero.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/absolute%20zero. Accessed 19 Sep. 2026.

Kids Definition

absolute zero

noun
: a hypothetical temperature that has never been reached, represents no heat at all, and is equal to approximately −273.15°C or −459.67°F

Medical Definition

absolute zero

noun
: a theoretical temperature characterized by complete absence of heat and equivalent to exactly −273.15°C or −459.67°F

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