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.
The rings arise because the metal softens as the can compresses, then stiffens, then compresses and stiffens again, repeating the pattern until the compression is complete—akin to something called homoclinic snaking. ArsTechnica, 2 May 2026 Will these Knicks stick to the process when the competition stiffens in the second round? Kristian Winfield, New York Daily News, 29 Apr. 2026 The journey of King Charles and the Queen consort had been planned for some time, well before relations between the United Kingdom and the United States stiffened due to international tensions, compounded by the assassination attempt on Trump at the White House Correspondents’ Dinner. Giorgia Olivieri, Vanity Fair, 28 Apr. 2026 If your soft-sided carrier has an insert to stiffen the bottom of the bag, don’t forget to remove and wash the insert, too. Nafeesah Allen, Better Homes & Gardens, 28 Apr. 2026 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

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Cite this Entry

“Stiffen.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/stiffen. Accessed 5 May. 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

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