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

Examples of kelvin in a Sentence

Recent Examples on the Web
Noun
In general, the range from warmest to coolest is warm white (2,700 kelvins and below), soft white (2,700–3,000 kelvins), bright or cool white (3,500–5,000 kelvins), and daylight (5,000-plus kelvins). Kat De Naoum, Better Homes & Gardens, 2 Jan. 2024 The material in the accretion disk is about a million kelvins, but the corona is a billion kelvins. Michael Greshko, Quanta Magazine, 12 Feb. 2024 In each device, a 40-nanometer-wide niobium-titanium nitride wire was cooled to about 2 kelvin (about -271 °C), rendering the wire superconductive. IEEE Spectrum, 1 Feb. 2024 Warm white bulbs are about 2,700 kelvins, whereas daylight bulbs are much brighter—more than 5,000 kelvins. Kat De Naoum, Better Homes & Gardens, 2 Jan. 2024 Liquid nitrogen boils at just 77 kelvins (-196 °C). IEEE Spectrum, 21 Dec. 2023 For example, cooling these classical servers down to the temperatures needed for quantum computers (1 kelvin or -272 °C) wouldn’t make the computers hyperefficient. IEEE Spectrum, 16 Nov. 2023 To do it, the researchers trapped deuterium ions in a cage of electric fields, flushed them with hydrogen gas and cooled everything down to an extremely chilly 15 kelvins. Elise Cutts, Scientific American, 4 Apr. 2023 Climate models suggest the planet has a temperature between 1,300 and 1,400 kelvins (between 1,880 and 2,060 Fahrenheit). Nola Taylor Tillman, Scientific American, 13 Apr. 2023

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'kelvin.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

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 19 Mar. 2024.

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
Etymology

Adjective

named for William Thomson, Lord Kelvin (1824–1907), British mathematician and physicist

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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