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
Kimberly Holland, Southern Living, 15 June 2025
Sukiyaki, created in the late 1900s, is a popular dish that features wagyu, sliced thin and cooked in a cast-iron pan on a portable tabletop grill, along with vegetables and tofu, in a sweet soy broth.
—Yukari Sakamoto, AFAR Media, 12 June 2025
Saveur Editors, Saveur, 5 June 2025
Deep to partial shade Soil Type: Nutrient-rich loam Soil pH: Acidic
Cast Iron Plant
When nothing else will grow beneath a huge tree, add some cast iron plants.
—Mary Marlowe Leverette, Southern Living, 4 June 2025
See All Example Sentences for cast-iron
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Adjective
Melt 1/4 cup of the butter in a 12-inch cast-iron skillet over medium.
—Kimberly Holland, Southern Living, 15 June 2025
Sukiyaki, created in the late 1900s, is a popular dish that features wagyu, sliced thin and cooked in a cast-iron pan on a portable tabletop grill, along with vegetables and tofu, in a sweet soy broth.
—Yukari Sakamoto, AFAR Media, 12 June 2025
Noun
The high-quality cast iron retains and balances high temps for an even, consistent cook.
—Saveur Editors, Saveur, 5 June 2025
Deep to partial shade Soil Type: Nutrient-rich loam Soil pH: Acidic
Cast Iron Plant
When nothing else will grow beneath a huge tree, add some cast iron plants.
—Mary Marlowe Leverette, Southern Living, 4 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 20 Jun. 2025.
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