cast-iron

1 of 2

adjective

ˈkast-ˈī(-ə)rn 

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

cast iron

2 of 2

noun

: 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

Synonyms of cast-iron

Adjective

• strict
• rigorous
• rigid

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

Adjective

Place the frozen biscuits on a metal sheet pan or in a cast-iron skillet; give them at least 1 inch of space to rise properly. —Alana Al-Hatlani, Southern Living, 6 Mar. 2026

Kitchen Utensils to Use Instead To protect your beloved cast-iron cookware, use the right kitchen utensils. —Olivia McIntosh, Martha Stewart, 5 Mar. 2026

Noun

Dutta recalled his grandmother always trying to force out the last drips from cartons and containers, while Tang had his own problems when cleaning his cast iron wok pan. —Andrew Paul, Popular Science, 5 Mar. 2026

Stick to wood, silicone, bamboo, or rounded metal utensils to keep your cast iron in top condition. —Olivia McIntosh, Martha Stewart, 5 Mar. 2026

Word History

First Known Use

Adjective

1692, in the meaning defined at sense 1

Noun

1664, in the meaning defined above

Rhymes for cast-iron

• aileron
• antiphon
• autobahn
• carillon
• castellan
• celadon
• cephalon
• chitosan
• cynodon
• denouement
• deuteron
• echelon

Kids Definition

cast iron

noun

: a hard brittle alloy of iron, carbon, and silicon shaped by being poured into a mold while melted