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 prime minister’s demeanor stiffened. Ted Johnson, Deadline, 19 Mar. 2026 Lower levels of the hormone can stiffen blood vessels and accelerate blockages. Tom Gavin, EverydayHealth.com, 18 Mar. 2026 What began as breathlessness hardened into silicosis, an irreversible disease that stiffens the lungs until even ordinary movement becomes effort. Dr. Céline Gounder, CBS News, 12 Mar. 2026 After the deputies put him back into the chair, Mitchell’s body stiffened, with his legs straight in front of him and his head lolling back. USA Today, 8 Mar. 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

Browse Nearby Words

Cite this Entry

“Stiffen.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/stiffen. Accessed 22 Mar. 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

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

More from Merriam-Webster