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Definitions

harden

[hahr-dn] / ˈhɑr dn /
VERB
make or become solid
Synonyms
STRONG
amalgamate anneal bake brace buttress cake calcify callous cement close clot coagulate compact congeal consolidate contract crystallize curdle dry firm fix fortify fossilize freeze gird indurate jell nerve ossify petrify precipitate press reinforce set settle solidify starch steel stiffen strengthen temper thicken toughen vitrify
WEAK
densify
Antonyms
STRONG
continue dilute discourage dishearten disjoin dissolve dissuade divide enlarge flex hurt let go liquefy loosen melt open separate soften thin unfix unsettle upset weaken
WEAK
be intolerant indulge spoil
VERB
accustom
Synonyms
STRONG
acclimate acclimatize adapt adjust blunt brutalize callous callus coarsen conform deaden develop discipline dull embitter habituate indurate inure numb paralyze roughen season steel stiffen strengthen stun stupefy teach train
WEAK
case-harden climatize make callous render insensitive
Antonyms
STRONG
disarrange disorder enliven neglect unfit weaken
WEAK
be intolerant indulge liquefy melt soften spoil

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.

The service takes technical measures to harden the security of its server network.

From Salon • Mar. 13, 2026

Here is his list of 11 stocks to harden your portfolio against Iran risk.

From MarketWatch • Mar. 13, 2026

Done right, market-structure legislation could harden the financial perimeter that underpins sanctions and law enforcement.

From Barron's • Feb. 5, 2026

The sides harden into their positions, using words they will probably come to regret.

From The Wall Street Journal • Jan. 26, 2026

Even if it caused her to harden toward Rosie, she’d never have caused her harm.

From "Water for Elephants" by Sara Gruen

From Roget's 21st Century Thesaurus, Third Edition Copyright © 2013 by the Philip Lief Group.