stiffen

verb

stiff·​en ˈsti-fən How to pronounce stiffen (audio)
stiffened; stiffening ˈsti-fə-niŋ How to pronounce stiffen (audio)
ˈstif-niŋ
Synonyms of stiffennext

intransitive verb

: to become stiff or stiffer
stiffener
ˈsti-fə-nər How to pronounce stiffen (audio)
ˈstif-nər
noun

Examples of stiffen in a Sentence

She stiffened when he grabbed her shoulder. The dogs stiffened in alarm. The law would stiffen penalties for tax evasion.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
These include stiffening of blood vessels, changes in heart muscle function and impaired ability of the cardiovascular system to respond to exertion. Katia Hetter, CNN Money, 16 Jan. 2026 So, stiffen the luxury tax penalties for the Dodgers and the other big spenders. Ken Rosenthal, New York Times, 16 Jan. 2026 Salt dries into white rings, while melting snow can cause uneven water stains that stiffen leather, dull suede, and discolor fabric. Katie Cloyd, Martha Stewart, 6 Jan. 2026 Outrage from the left about that maneuver stiffened Democratic spirits for a confrontation in the fall. Niall Stanage, The Hill, 31 Dec. 2025 See All Example Sentences for stiffen

Word History

First Known Use

15th century, in the meaning defined at transitive sense

Time Traveler
The first known use of stiffen was in the 15th century

Browse Nearby Words

Cite this Entry

“Stiffen.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/stiffen. Accessed 25 Jan. 2026.

Kids Definition

stiffen

verb
stiff·​en ˈstif-ən How to pronounce stiffen (audio)
stiffened; stiffening -(ə-)niŋ How to pronounce stiffen (audio)
: to make or become stiff or stiffer
stiffener noun

More from Merriam-Webster on stiffen

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