kelvin

1 of 2

noun

kel·​vin ˈkel-vən How to pronounce kelvin (audio)
plural kelvins
: the base unit of temperature in the International System of Units that is defined by setting the fixed numerical value of the Boltzmann constant to be 1.380649 x 10–23 joules per kelvin and that is equal to 1/273.16 of the Kelvin scale temperature of the triple point of water
abbreviation K

Kelvin

2 of 2

adjective

: relating to, conforming to, or having a thermometric scale on which the unit of measurement equals the Celsius degree and according to which absolute zero is 0 K, the equivalent of −273.15°C

Example Sentences

Recent Examples on the Web
Noun
Back in 1998, though, astronomers saw a powerful flare erupt from Barnard’s star, causing its temperature to soar from about 3,100 kelvin to at least 8,000. Amber Jorgenson, Discover Magazine, 14 Nov. 2018 Inside the sun, where nuclear fusion occurs, temperatures can swell to 15 million kelvin. Jennifer Leman, Popular Mechanics, 22 Nov. 2022 About 5,000 light-years away, this star system is just 1 kelvin above absolute zero. Stephen Ornes, Discover Magazine, 25 June 2019 At night, the surface of even the closest planet to the sun, Mercury, drops to about 95 kelvin. Jennifer Leman, Popular Mechanics, 22 Nov. 2022 At night, the surface of even the closest planet to the sun, Mercury, drops to about 95 kelvin. Jennifer Leman, Popular Mechanics, 22 Nov. 2022 The second challenge was to ensure the detectors worked properly by achieving a temperature of 7 kelvin (266º C below freezing). Dhananjay Khadilkar, Ars Technica, 10 Aug. 2022 Lightforce takes special care to ensure its driving lights operate at 5,000 kelvin, which should be considered an ideal color temperature. Wes Siler, Outside Online, 18 Aug. 2020 The color temperature of daylight varies with conditions but is commonly understood to range from 5,000 to 6,500 kelvin. Wes Siler, Outside Online, 18 Aug. 2020 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'kelvin.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History

Etymology

Adjective

William Thomson, Lord Kelvin

First Known Use

Noun

1968, in the meaning defined above

Adjective

1908, in the meaning defined above

Time Traveler
The first known use of kelvin was in 1908

Dictionary Entries Near kelvin

Cite this Entry

“Kelvin.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/kelvin. Accessed 3 Feb. 2023.

Kids Definition

kelvin

1 of 2 noun
kel·​vin ˈkel-vən How to pronounce kelvin (audio)
: a unit of temperature equal to 1/273.16 of the Kelvin scale temperature of the triple point of water

Kelvin

2 of 2 adjective
: relating to or having a temperature scale on which the unit of measurement is the same size as the Celsius degree and according to which absolute zero is 0 K (-273.15°C)
abbreviation K

Medical Definition

kelvin

1 of 2 noun
kel·​vin ˈkel-vən How to pronounce kelvin (audio)
: the base unit of temperature in the International System of Units that is equal to 1/273.16 of the Kelvin scale temperature of the triple point of water and also to the Celsius degree

Kelvin

2 of 2 adjective
: relating to, conforming to, or being the Kelvin scale

Biographical Definition

Kelvin

biographical name

Kel·​vin ˈkel-vən How to pronounce Kelvin (audio)
1st Baron 1824–1907 William Thomson British mathematician and physicist

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