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
Alicia Geigel, Southern Living, 7 Jan. 2026
In the ruins of the kitchen sat two cast-iron Le Creuset stew pots — the only survivors.
—Jonathan Taplin, Rolling Stone, 7 Jan. 2026
Mary Marlowe Leverette, The Spruce, 9 Jan. 2026
Le Creuset Signature 8-Quart Oval Dutch Oven Designed with enameled cast iron, this round 8-quart pot heats quickly and retains heat and flavor efficiently.
—Toni Sutton, PEOPLE, 4 Jan. 2026
See All Example Sentences for cast-iron
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Adjective
Unlike traditional cast-iron skillets, this one is coated in a black satin enamel that prevents food from sticking to the bottom, resists rust, and doesn’t require seasoning or regular upkeep.
—Alicia Geigel, Southern Living, 7 Jan. 2026
In the ruins of the kitchen sat two cast-iron Le Creuset stew pots — the only survivors.
—Jonathan Taplin, Rolling Stone, 7 Jan. 2026
Noun
Avoid putting wood, hand-painted, or cast iron pieces in the dishwasher.
—Mary Marlowe Leverette, The Spruce, 9 Jan. 2026
Le Creuset Signature 8-Quart Oval Dutch Oven Designed with enameled cast iron, this round 8-quart pot heats quickly and retains heat and flavor efficiently.
—Toni Sutton, PEOPLE, 4 Jan. 2026
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 15 Jan. 2026.
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