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Synonyms

stiffen

American  
[stif-uhn] / ˈstɪf ən /

verb (used with object)

  1. to make stiff.


verb (used without object)

  1. to become stiff.

  2. to become suddenly tense, rigid, or taut, as in bracing oneself for or drawing back from shock, fear, or displeasure.

    He stiffened, expecting to hear the worst.

stiffen British  
/ ˈstɪfən /

verb

  1. to make or become stiff or stiffer

  2. (intr) to become suddenly tense or unyielding

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

  • overstiffen verb
  • stiffener noun
  • unstiffened adjective

Etymology

Origin of stiffen

First recorded in 1490–1500; stiff + -en 1

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

She has also vowed to stiffen prison sentences and to impose a state of emergency in areas worst hit by crime.

From Barron's • Feb. 1, 2026

Redick looked as if he might stiffen under the postseason spotlight, the rookie coach uncharacteristically a man of few words and no smiles in his pregame news conference.

From Los Angeles Times • Apr. 20, 2025

Nonetheless, this is an important move that can help stiffen the spines at other schools.

From Salon • Apr. 16, 2025

The summit in London was an attempt by the prime minister both to calm diplomatic brows and stiffen diplomatic sinews.

From BBC • Mar. 2, 2025

Ray reaches over and half hugs me, but I stiffen, so he knocks me gently on the head with his fist.

From "The Tenth Mistake of Hank Hooperman" by Gennifer Choldenko