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

For adults especially, that increases their risk of heart attacks and strokes because it causes plaque-forming particles to build up in their arteries over time, hardening and narrowing them.

From The Wall Street Journal • Mar. 13, 2026

For the architect, who has spent much of his 45-year career designing for luxury, hardening a home against wildfire has brought a new kind of luxury to his homes: peace of mind.

From Los Angeles Times • Mar. 2, 2026

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

From BBC • Feb. 24, 2026

Despite her age or because of it, Celia advances steadily through the fields, hardening her muscles with every step, every swing.

From "Dreaming in Cuban" by Cristina García

Related Words

• crystallization