harden

verb hard·en \ ˈhär-dᵊn \

Updated on: 8 Apr 2018

Definition of harden

hardened; hardening play \ˈhärd-niŋ, ˈhär-dᵊn-iŋ\

transitive verb

1 : to make hard or harder

2 : to confirm in disposition, feelings, or action; especially : to make callous

hardened his heart

3 a : inure, toughen

harden troops

b : to inure to unfavorable environmental conditions (such as cold) —often used with off

harden off seedlings before transplanting

4 : to protect from blast, heat, or radiation (as by a thick barrier or placement underground)

intransitive verb

1 : to become hard or harder

2 a : to become firm, stable, or settled

b : to assume an appearance of harshness or severity

her face hardened at the thought

3 : to become gradually acclimatized to unfavorable conditions —often used with off

plants hardened off before the first frost

See harden defined for English-language learners

See harden defined for kids

Examples of harden in a Sentence

The presence of certain substances in the blood can cause the arteries to harden.
These additives are designed to harden the steel.
substances that can harden the arteries
The news has hardened opposition to the government.
He had been hardened by his years of military service.

Recent Examples of harden from the Web

Back in El Salvador, the gang was led by veterans hardened by decades of violence.

— hannah dreier, Daily Intelligencer, "The Betrayal of Triste," 2 Apr. 2018
Finding its way, St. Mary sent a bolt of needed energy into the Miller community, hardened by shuttered school buildings and decline.

— carole carlson, Post-Tribune, "The comeback church: Keeping the faith saved Gary's St. Mary of the Lake," 31 Mar. 2018
In the hardening political atmosphere, 90-minute bursts of respite around football can't be a bad thing. ___ John Leicester is an international sports columnist for The Associated Press.

— john leicester, Fox News, "Column: World Cup offers chance for respite from Russia heat," 28 Mar. 2018
The funding comes amid a hardening stance across the nation toward recipients of public benefits.

— terrence mccoy, Washington Post, "Spending bill addresses crushing backlog of federal disability claims," 28 Mar. 2018
In many ways, Pritzker's win was a sign that Democrats have hardened from that debacle.

— ben joravsky, Chicago Reader, "Don't cry, progressives: Pritzker win shows Dems more pragmatic, practical after Trump loss," 21 Mar. 2018
Figuring out those vulnerabilities is just the first step in hardening our satellites and power grid against a solar catastrophe.

— jason daley, Smithsonian, "Earthlings: There’s No Need to Freak Out About Tonight’s Solar Storm," 14 Mar. 2018
But Cypress Falls coach Richard Flores knows Region III-6A only hardens for the defending Class 6A champions.

— adam coleman, Houston Chronicle, "Cypress Falls boys beat Bellaire in bi-district playoff game," 20 Feb. 2018
Apple has placed a great deal of emphasis on its boot code in security hardening efforts.

— sean gallagher, Ars Technica, "Leak of iBoot code to GitHub could potentially help iPhone jailbreakers [Updated]," 8 Feb. 2018

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

First Known Use of harden

13th century

harden Synonyms

Harden

biographical name Har·den \ ˈhär-dᵊn \

Definition of Harden

Sir Arthur 1865–1940 English chemist

Harden

biographical name

Definition of Harden

Maximilian 1861–1927 originally Felix Ernst Witkowski German writer

HARDEN Defined for English Language Learners

harden

verb

Definition of harden for English Language Learners

: to become hard or firm or to make (something) hard or firm
: to become more definite and strongly felt or to make (something) more definite and strongly felt
: to make (someone) hard : to make (someone) less emotional and less likely to feel sorry for other people