- present participle of harden.
hardening
Americannoun
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a material that hardens another, as an alloy added to iron to make steel.
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the process of becoming hard or rigid.
noun
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the act or process of becoming or making hard
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a substance added to another substance or material to make it harder
Etymology
Origin of hardening
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.
Kirchner’s disappearance looms over what has become ground zero for a hardening resistance to the world’s hottest technology.
From The Wall Street Journal ● Jul. 12, 2026
It marks a wider trend of governments hardening their stance on undocumented migration, with many, including the UK and Italy, adopting measures aimed at deterring it.
From BBC ● Jul. 4, 2026
UV light is used for air purification, curing resins in 3D printing, hardening gels in dental fillings, and even applications such as nail treatments.
From Science Daily ● Jun. 26, 2026
Horvath said the county hopes to receive tens of millions of dollars in state funding for additional brush clearance, fuel modification, home hardening and other initiatives.
From Los Angeles Times ● Jun. 26, 2026
It is cold, cold; so cold that the grey heavy sky is full of snow, which when it falls will settle for all winter as the ground is hardening to receive it.
From "Dracula" by Bram Stoker
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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.