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

Heat a cast-iron or saute skillet over medium heat. —Caron Golden, San Diego Union-Tribune, 22 Apr. 2026

The family room offers three walls of windows, a fireplace with an authentic late-1800s cast-iron facade, granite mantel and a polished nickel and crystal drum chandelier. —Saleema Syed, Chicago Tribune, 21 Apr. 2026

Noun

There are a whole host of desserts to be made using a cast iron skillet, and this is just the tip of the iceberg. —Patricia S York, Southern Living, 19 Apr. 2026

Crafted from enameled cast iron, the dish is designed to provide steady, even heat for cooking meats and vegetables. —Michele Laufik, Martha Stewart, 10 Apr. 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