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
Molly Allen, Travel + Leisure, 28 Oct. 2025
Heat a 10-inch cast-iron skillet over medium-high.
—Ann Taylor Pittman, Southern Living, 18 Oct. 2025
Symiah Dorsey, Southern Living, 25 Oct. 2025
The Le Creuset sale includes cast iron grills, Dutch ovens for all your soup, stew, and chili needs, coffee mugs, and stoneware baking dishes.
—Emily Weaver, PEOPLE, 22 Oct. 2025
See All Example Sentences for cast-iron
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Adjective
Each oceanfront room features a balcony looking out toward a towering haystack rock in the sea, plus gas fireplaces, pillow-top mattresses, and cast-iron soaking tubs.
—Molly Allen, Travel + Leisure, 28 Oct. 2025
Heat a 10-inch cast-iron skillet over medium-high.
—Ann Taylor Pittman, Southern Living, 18 Oct. 2025
Noun
The cast iron skillet works its magic, and the puff pastry squares give it a very special twist.
—Symiah Dorsey, Southern Living, 25 Oct. 2025
The Le Creuset sale includes cast iron grills, Dutch ovens for all your soup, stew, and chili needs, coffee mugs, and stoneware baking dishes.
—Emily Weaver, PEOPLE, 22 Oct. 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 31 Oct. 2025.
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