hardening

American  

[hahr-dn-ing] / ˈhɑr dn ɪŋ /

noun

1. a material that hardens another, as an alloy added to iron to make steel.

2. the process of becoming hard or rigid.

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hardening British  

/ ˈhɑːdənɪŋ /

noun

1. the act or process of becoming or making hard

2. a substance added to another substance or material to make it harder

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Etymology

Origin of hardening

First recorded in 1620–30; harden + -ing ¹

Example Sentences

A 2018 server breach caused by a third-party data center vulnerability prompted NordVPN to accelerate its security hardening and audit schedule.

From Salon • Mar. 27, 2026

Satellite imagery suggests that Iran has been hardening entrances to its nuclear sites in case of attack.

From The Wall Street Journal • Feb. 27, 2026

The RSF set up a parallel government last year, hardening the de facto division of the country.

From BBC • Feb. 24, 2026

Pérez’s bill would establish home hardening and defensible space measures set by the insurance commissioner, though Balber said she expects the Safer from Wildfires program would “inform” the new standards.

From Los Angeles Times • Feb. 19, 2026

I was kicked again under the table and, looking, saw Frances, Robert's lady, her chin lifting and her face hardening.

From "The Sun Also Rises" by Ernest Hemingway

Related Words

• crystallization