coolant

American  

[koo-luhnt] / ˈku lənt /

noun

• coolants
  plural

1. a substance, usually a liquid or a gas, used to reduce the temperature of a system below a specified value by conducting away the heat produced in the operation of the system, as the liquid in an automobile cooling system or the fluid that removes heat from the core of a nuclear reactor.

2. a lubricant that dissipates the heat caused by friction.

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coolant British  

/ ˈkuːlənt /

noun

1. a fluid used to cool a system or to transfer heat from one part of it to another

2. a liquid, such as an emulsion of oil, water, and soft soap, used to lubricate and cool the workpiece and cutting tool during machining

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Other Word Forms

Noun Inflected Forms

• coolants
  plural

Etymology

Origin of coolant

First recorded in 1925–30; cool + -ant

Example Sentences

See Examples For:

coolant coolants

Specs can digitize a chess board, provide AR-guided training for shooting basketballs and even highlight the coolant reservoir under the hood of a car, according to videos and photos online.

From MarketWatch ● Jun. 17, 2026

Engineers will carry out detailed inspections, collect flight data, remove reusable components such as avionics, and address any remaining hazards like excess fuel or coolant.

From Science Daily ● May 4, 2026

Kairos uses molten fluoride salt as a coolant, allowing it to operate at low pressures and high temperatures, and it also has a smaller demonstration reactor under construction in Oak Ridge.

From The Wall Street Journal ● Apr. 23, 2026

A student from Hurlford, she then went down a rabbit hole looking at the amount of water that would be needed for coolant, the process which stops the computer chips there from overheating.

From BBC ● Mar. 1, 2026

Rods remain submerged in the coolant and radiation shield of the water while they are being moved.

From "Meltdown" by Deirdre Langeland

It has also acquired Anchemco’s automotive business specializing in brake fluids, coolants and diesel exhaust fluids.

From The Wall Street Journal ● Apr. 21, 2026

These coolants are essential in fusion reactors to extract heat and breed tritium, but their corrosive nature threatens the integrity of the structural materials used.

From Science Daily ● Nov. 25, 2024

Whereas other advanced reactor designs rely on exotic coolants, NuScale’s sticks to water.

From Science Magazine ● Nov. 10, 2023

Trees are natural coolants and lower the risk of respiratory and heat-related illnesses such as those seen during this summer’s record heat wave.

From National Geographic ● Oct. 9, 2023

She was frosted already by the interhull coolants, and as I approached the high port slid open and the exitway was extruded, a graceful curve down onto the ice.

From "The Left Hand of Darkness" by Ursula K. Le Guin