1
: made of cast iron
2
: resembling cast iron: such as
a
: capable of withstanding great strain
a cast-iron stomach
b
: not admitting change, adaptation, or exception : rigid
a cast-iron will
c
British
: not likely to fail or be broken : airtight
"Clever idea, Black, getting yourself seen on a safe station platform … gave you a cast-iron excuse not to leave your hidey-hole in future, didn't it?"—
J. K. Rowling
J. K. Rowling
: a commercial alloy of iron, carbon, and silicon that is cast in a mold and is hard, brittle, nonmalleable, and incapable of being hammer-welded but more easily fusible than steel
Examples of cast-iron in a Sentence
Adjective
lost weight only after a cast-iron adherence to his diet
he has a cast-iron faith in his innate ability to overcome any adversity that life might throw against him
Noun
The fence is made of cast iron.
Recent Examples on the Web
David Nikel, Forbes.com, 28 June 2025
All were 12-cup muffin pans, except for Le Creuset’s six-cup cast-iron model.
—Mark Marino, Bon Appetit Magazine, 26 June 2025
Bestreviews, Chicago Tribune, 17 June 2025
This set of 10 cast iron hooks is strong and easy to hang anywhere.
—Christopher Murray
May Earn A Commission If You Buy Through Our Referral Links. This Content Was Created By A Team That Works Independently From The Fox Newsroom., FOXNews.com, 12 June 2025
See All Example Sentences for cast-iron
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Adjective
Strolling through downtown Leeds reveals a patchwork of eras, from the cast-iron and mosaic elegance of the Victoria Quarter to the soaring glass canopy of Trinity Leeds.
—David Nikel, Forbes.com, 28 June 2025
All were 12-cup muffin pans, except for Le Creuset’s six-cup cast-iron model.
—Mark Marino, Bon Appetit Magazine, 26 June 2025
Noun
Seasoned cast iron presses are nonstick, but they can also be finished in silver and powder coating.
—Bestreviews, Chicago Tribune, 17 June 2025
This set of 10 cast iron hooks is strong and easy to hang anywhere.
—Christopher Murray
May Earn A Commission If You Buy Through Our Referral Links. This Content Was Created By A Team That Works Independently From The Fox Newsroom., FOXNews.com, 12 June 2025
See All Example Sentences for cast-iron
Cite this Entry
“Cast-iron.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/cast-iron. Accessed 2 Jul. 2025.
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