coolant

[koo-luh nt]

noun

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.
a lubricant that dissipates the heat caused by friction.

Origin of coolant

First recorded in 1925–30; cool + -ant

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for coolant

Contemporary Examples of coolant

Once the system is powered on, coolant flows to the bottom, extracts heat from the soil, and flows back up to be cooled again.
Fukushima N-Plant Will Be Surrounded by a Wall of Ice
Josh Dzieza
September 4, 2013

British Dictionary definitions for coolant

coolant

noun

a fluid used to cool a system or to transfer heat from one part of it to another
a liquid, such as an emulsion of oil, water, and soft soap, used to lubricate and cool the workpiece and cutting tool during machining

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for coolant

"radiator fluid," 1930, from cool (adj.) + -ant.