as in to freeze
to become physically firm or solid
wait for the modeling clay to firm up before handling the finished pot
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Example Sentences
Recent Examples of Synonyms for firm (up)
Verb
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Transporter 14's upper stage proceeded to deploy its payloads and release a plume of rocket propellant prior to re-entering Earth's atmosphere, which quickly froze and reflected sunlight, becoming visible to eagle-eyed stargazers in Europe.—
Anthony Wood,
Space.com,
25 June 2025 -
Even with the help of the train, rescuers hiked a mile along an exposed ridgeline above 5,000 feet, encountering high winds and freezing temperatures, to reach Wilson.—
Owen Clarke,
Outside Online,
24 June 2025
Verb
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Tehran's rejection shows that U.S. pressure has hardened its stance, narrowing oversight after damage to its nuclear sites and suspended inspections.—
Amir Daftari,
MSNBC Newsweek,
27 June 2025
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Many had been taught to feel shame in Native culture and language at Indian boarding schools; others had been hardened by prison stints or by the harsh realities of urban poverty.—
Nick Estes,
New Yorker,
26 June 2025
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“Firm (up).” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/firm%20%28up%29. Accessed 3 Jul. 2025.
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