as in to freeze
to become physically firm or solid
wait for the modeling clay to firm up before handling the finished pot
Synonyms & Similar Words
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Example Sentences
Recent Examples of Synonyms for firm (up)
Verb
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Trump said late Thursday that President Vladimir Putin had agreed to a temporary pause in targeting Kyiv and other places as the region experiences freezing temperatures that have brought widespread hardship to civilians.—
Arkansas Online,
Arkansas Online,
31 Jan. 2026 -
Florida freeze Extreme cold and freeze alerts were hoisted for much of the state on Friday in advance of the worst cold.—
Mary Gilbert,
CNN Money,
30 Jan. 2026
Verb
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Perhaps a serious literary consideration of ambition, one that breaks through the shell of Millennial disillusionment that has hardened around the subject in recent years, would need to follow Orlean’s lead in focusing on craft.—
Lily Meyer,
The Atlantic,
29 Jan. 2026
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Its silvery surface is scarred by dark regions known as lunar maria, where molten lava once flooded enormous impact basins before hardening to create enormous basaltic plains.—
Anthony Wood,
Space.com,
28 Jan. 2026
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Cite this Entry
“Firm (up).” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/firm%20%28up%29. Accessed 2 Feb. 2026.
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