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.
Group 1 is pulmonary arterial hypertension, a rare and severe version that occurs when blood vessels in the lungs narrow and stiffen. Elizabeth Cooney, STAT, 26 June 2026 Pulisic played a dynamic first half in the Americans' historic 4-1 victory over Paraguay to open their home World Cup nearly two weeks ago, but the AC Milan midfielder came off at halftime after an injury from training stiffened up. ABC News, 24 June 2026 For seven-and-a-half years, Ladd had dealt with idiopathic pulmonary fibrosis (IPF), a progressive lung disease that stiffens and scars the lungs. Helen Carefoot, Flow Space, 24 June 2026 Major media companies operating traditional linear networks have been under pressure in recent years amid stiffening competition from large tech rivals as programming migrates to streaming. Dade Hayes, Deadline, 18 June 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 6 Jul. 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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