stiff·​en | \ ˈsti-fən \
stiffened; stiffening\ ˈsti-​fə-​niŋ , ˈstif-​niŋ \

Definition of stiffen

intransitive verb

: to become stiff or stiffer

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Other Words from stiffen

stiffener \ ˈsti-​fə-​nər , ˈstif-​nər \ noun

Synonyms & Antonyms for stiffen


harden, harshen, strengthen, toughen


ameliorate, ease

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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.
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Recent Examples on the Web

This is probably thanks, in part, to the stiffening effect of Republican policy on animal spirits. The Economist, "Business in the Republicans’ America is flourishing, but also changing," 24 May 2018 At the same time, collagen production drops off and elastic fibers begin to stiffen, laying the groundwork for wrinkles and sagging. Jolene Edgar, Allure, "The Truth About Growth Factors in Skin Care and Why They're Controversial," 2 Aug. 2018 His tiny arms and legs would stiffen for a few seconds as many as 30 times per hour. Sarah Elizabeth Richards,, "Rapid sequencing of babies' genes may save lives," 11 June 2018 For the chassis, that means highly stiffened joints between structures and optimized cross sections for better stability, comfort, and agility (to the degree that a seven-passenger SUV can be agile). Eric Bangeman, Ars Technica, "Safety first, last, and always: The Subaru Ascent, reviewed," 25 Oct. 2018 But from there, the defense stiffened — the Bears ran for just 42 yards on 14 plays in the first half and had no gain of longer than 18. Bob Condotta, The Seattle Times, "Seahawks flop in Chicago and lose to Bears on Monday Night Football behind anemic offense," 17 Sep. 2018 Two South American nations are stiffening entry requirements for the flood of Venezuelans fleeing their nation's economic and humanitarian crisis, a move that could make their plight even more arduous. Fox News, "Peru, Ecuador tighten requirements for Venezuela migrants," 17 Aug. 2018 Though its share of the market is smaller than those of the top players, AlixPartners and Alvarez & Marsal, its entry has stiffened competition. The Economist, "McKinsey manages to get itself sued for racketeering," 19 May 2018 Deportations were relatively rare until 1996, when Congress passed a law stiffening penalties for undocumented immigrants. Liz Goodwin,, "Trump’s immigration crackdown gives the left a rallying cry: ‘Abolish ICE’," 28 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'stiffen.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of stiffen

15th century, in the meaning defined at transitive sense

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Statistics for stiffen

Last Updated

6 Jan 2019

Look-up Popularity

Time Traveler for stiffen

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

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More Definitions for stiffen



English Language Learners Definition of stiffen

: to stop moving and become completely still especially because of fear, anger, etc.

: to become painful to move or use

: to become more severe or strong or to make (something) more severe or strong


stiff·​en | \ ˈsti-fən \
stiffened; stiffening

Kids Definition of stiffen

1 : to make or become stiff or stiffer The paper stiffened as it dried.
2 : to become tense and still He stiffened with suspicion.

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More from Merriam-Webster on stiffen

Rhyming Dictionary: Words that rhyme with stiffen

Thesaurus: All synonyms and antonyms for stiffen

Spanish Central: Translation of stiffen

Nglish: Translation of stiffen for Spanish Speakers

Britannica English: Translation of stiffen for Arabic Speakers

Comments on stiffen

What made you want to look up stiffen? Please tell us where you read or heard it (including the quote, if possible).


someone who never drinks alcohol

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