STIFFEN Synonyms: 9 Similar and Opposite Words

stiffen

verb

ˈsti-fən

Definition of stiffen

as in to strengthen

to make more harsh, uncompromising, or severe plans to further stiffen the already onerous requirements for admission to the elite military unit

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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.

Recent Examples of stiffen This remains soft during low-energy movement but stiffens upon high-impact force. — Arthur Zaczkiewicz, Footwear News, 27 July 2026 Older dogs stiffen up, scratch more, lose a step, and their owners want to help. — Daniel Fusch, USA Today, 17 July 2026 Graham's aorta, at 71, tore, a dissection along a wall stiffened by decades of what the medical examiner called arteriosclerotic cardiovascular disease. — Dr. Céline Gounder, CBS News, 13 July 2026 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 See All Example Sentences for stiffen

Recent Examples of Synonyms for stiffen

strengthen

Verb

The Iranian trade office on Friday called the agreement with Oman part of Tehran's broader push to strengthen economic ties with regional partners through trade diplomacy and improved logistics infrastructure.

— Khaled Wassef, CBS News, 21 Aug. 2026
However, the same methodology was used throughout the study period, which strengthens the finding of an increase over time.

— Faye Chiu, CNN Money, 21 Aug. 2026

Definition of strengthen

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stiffed

stiffen

stiffened

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“Stiffen.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/stiffen. Accessed 26 Aug. 2026.

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Synonyms of stiffen

verb

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