to make hard or harder.
to harden steel.
to make pitiless or unfeeling.
to harden one's heart.
to make rigid or unyielding; stiffen.
The rigors of poverty hardened his personality.
to strengthen or confirm, especially with reference to character, intentions, feelings, etc.; reinforce.
to make hardy, robust, or capable of endurance; toughen.
Military. to reinforce the structure of (a military or strategic installation) to protect it from nuclear bombardment.
to become hard or harder.
to become pitiless or unfeeling.
to become rigid or unyielding; stiffen.
His personality hardened over the years.
to become confirmed or strengthened.
His resistance hardened.
to become inured or toughened.
The troops hardened under constant fire.
Commerce. (of a market, prices, etc.)
to cease to fluctuate; firm.
When the speculators withdrew from the market, the prices hardened.
to rise higher.
to make or become hard or harder; freeze, stiffen, or set
to make or become more hardy, tough, or unfeeling
to make or become stronger or firmer
they hardened defences
to make or become more resolute or set
hardened in his resolve
(intr) commerce
(of prices, a market, etc) to cease to fluctuate
(of price) to rise higher
Middle English word dating back to 1150–1200; see origin at hard, -en 1
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Already, the excess heat in the tank has caused the MMA to harden and clog the failing tank’s valves, rendering it impossible for crews to drain the dangerous chemical or add stabilizing agents, Freeman said.
From Los Angeles Times • May 23, 2026
The drone attack is also likely to harden the stance of the UAE, which has grown increasingly hawkish since the war began.
From Barron's • May 18, 2026
The impact of this, he said, is Israeli troops "having to move more cautiously, harden positions, use physical protective measures such as nets and cages, and devote more attention to immediate local defence".
From BBC • May 16, 2026
The service takes technical measures to harden the security of its server network.
From Salon • Mar. 13, 2026
He takes another step forward and my muscles harden and tense, ready to run if I have to.
From "The Brightwood Code" by Monica Hesse
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.
