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
Matthew Sedacca, Curbed, 22 July 2025
The door fits 12-inch pizza peels and 10-inch cast-iron skillets.
—Adrienne So, Wired News, 21 July 2025
Dana Afana, Freep.com, 12 July 2025
Le Creuset Enameled Cast Iron Skillet This cast iron skillet is durable, versatile, and perfect for everything from searing steaks to baking biscuits — and my personal favorite?
—Jeaneen Russell, People.com, 8 July 2025
See All Example Sentences for cast-iron
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Adjective
The windowed bathroom is an Art Deco stunner in its own right: vintage tiles and the original cast-iron tub, plus a sweet floral wallpaper no buyer should ever strip.
—Matthew Sedacca, Curbed, 22 July 2025
The door fits 12-inch pizza peels and 10-inch cast-iron skillets.
—Adrienne So, Wired News, 21 July 2025
Noun
Residents filed the lawsuit a day before Detroit's Historic District Commission voted to proceed with a revised version of the project, which includes using cast iron manhole covers instead of steam vent stacks.
—Dana Afana, Freep.com, 12 July 2025
Le Creuset Enameled Cast Iron Skillet This cast iron skillet is durable, versatile, and perfect for everything from searing steaks to baking biscuits — and my personal favorite?
—Jeaneen Russell, People.com, 8 July 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 27 Jul. 2025.
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