cool·ant | \ˈkü-lənt \

Definition of coolant 

: a usually fluid cooling agent

Examples of coolant in a Sentence

Recent Examples on the Web

Likely Cause: There’s a leak somewhere in your coolant system. Popular Mechanics, "The Lightning-Fast Guide to Figuring Out What's Wrong With Your Car," 21 Nov. 2017 The technician put in 5 pounds of new coolant to get the system to work. Cathy Cunningham,, "Owner of defective Lennox AC unit asks: Can I opt out of class action and personally sue dealer who sold me unit?," 21 June 2018 Matula took it off before the coolant could soak through and burn his skin under a class T-shirt. Amy B Wang, Washington Post, "A teen nearly missed his graduation because of antifreeze burns. Deputies stepped in to help.," 11 June 2018 The airplane will need a cooling system to handle that heat, and Bowcutt says Boeing is looking into ways to use fuels like liquid methane to double as coolants, instead of water. Joe Pappalardo, Popular Mechanics, "How Boeing's Hypersonic Passenger Plane Concept Works," 26 June 2018 At CANEL, Pratt & Whitney also experimented with systems based on other coolants, including supercritical water (in which the water/steam is kept at extremely high pressures that force it to remain a fluid), sodium, and lithium. Sean Gallagher, Ars Technica, "Best bad idea ever? Why Putin’s nuclear-powered missile is possible… and awful," 22 Mar. 2018 The result is a sub that's quieter than any other diesel, and even quieter than its nuclear cousins which require a constant churn of coolant that can give away their position. Eric Limer, Popular Mechanics, "How a Plucky Swedish Sub Took Out a US Carrier All on Its Own," 13 Apr. 2018 His car, which has a broken coolant system, took a few tries to start. Kathleen Joyce, Fox News, "New York millennial finally leaves his parents' home, but first calls cops on his dad over Legos," 1 June 2018 Use air conditioning, because modern car coolant systems are actually more fuel-efficient than the drag created by driving with the windows open. Ben Popken /, NBC News, "Gas will cost drivers $1 billion more this Memorial Day weekend," 25 May 2018

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

See More

First Known Use of coolant

1915, in the meaning defined above

History and Etymology for coolant

cool entry 2 + -ant entry 1

Keep scrolling for more

Learn More about coolant

Statistics for coolant

Last Updated

11 Sep 2018

Look-up Popularity

Time Traveler for coolant

The first known use of coolant was in 1915

See more words from the same year

Keep scrolling for more

More Definitions for coolant



English Language Learners Definition of coolant

: a liquid that is used to cool an engine or machine

Keep scrolling for more

More from Merriam-Webster on coolant

Spanish Central: Translation of coolant

Nglish: Translation of coolant for Spanish Speakers

Britannica English: Translation of coolant for Arabic Speakers Encyclopedia article about coolant

Comments on coolant

What made you want to look up coolant? Please tell us where you read or heard it (including the quote, if possible).


to reject or criticize sharply

Get Word of the Day daily email!

Test Your Vocabulary

Words from Greek and Roman Mythology Quiz

  • the-triumph-of-venus-by-alessandro-magnasco
  • Boreal comes from the name of the ancient Greek god of which wind?
True or False

Test your knowledge - and maybe learn something along the way.

Bee Cubed

Test Your Knowledge - and learn some interesting things along the way.


Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!