retardant
Americannoun
adjective
noun
adjective
Other Word Forms
Etymology
Origin of retardant
Explanation
A retardant is anything that prevents something from happening, or inhibits it from growing or spreading. Using a rust retardant on your car, for example, should help keep it from getting rusty. A fire or flame retardant is a type of chemical that stops fire from starting or spreading. Sometimes fire retardants are sprayed or dumped on a fire to put it out, like the foam fire retardant you might spray from a hand-held fire extinguisher onto a grease fire in a kitchen. Retardant comes from the verb retard, "make slow, or make slower."
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
I pay for a private fire department, and we have built-in retardant sprayers.
From The Wall Street Journal ● Jun. 23, 2026
Sunshine Silver Mining & Refining, which also mines copper and antimony, a flame retardant mineral, could be a backdoor AI play given the demand for wiring in data centers.
From Barron's ● Jun. 2, 2026
Among the synthetic products, 19 claimed to be flame retardant, three were labeled water resistant, nine advertised heat resistance, and three promoted "green" claims such as "no PVC" or "non-toxic."
From Science Daily ● Feb. 19, 2026
Ventura County fire officials said they followed protocol when they left the Balcom fire — clearing containment lines, dropping retardant, and using a drone with an infrared camera to identify lingering heat.
From Los Angeles Times ● Jan. 30, 2026
The fire retardant hadn’t hit that spot, and something there seethed and burned.
From "Two Degrees" by Alan Gratz
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
