hardened; hardening
ˈhärd-niŋ
ˈhär-dᵊn-iŋ
1
: to make hard or harder
2
: to confirm in disposition, feelings, or action
especially
: to make callous
hardened his heart
3
4
: to protect from blast, heat, or radiation (as by a thick barrier or placement underground)
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
Cite this Entry
“Harden.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/harden. Accessed 7 Sep. 2026.
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