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

There’s trout almondine with rice pilaf from California’s Sequoia National Park – golden trout live in those high-elevation lakes and streams – and cast-iron rib eyes from Lassen Volcanic National Park, which has a history of cattle ranching. —John Metcalfe, Mercury News, 11 Mar. 2026

Out of all kitchen cookware, gadgets, and appliances, Miller believes that every kitchen should have a reliable cast-iron skillet, like this one from Lodge that earned our best overall pick out of 22 comparable options. —Alicia Geigel, Southern Living, 8 Mar. 2026

Noun

Having a couple of spatulas on hand — one silicone, one metal — covers the full range of cooking tasks, from delicate eggs in a nonstick pan to searing burgers on cast iron. —Kansas City Star, 11 Mar. 2026

While standard cast iron typically requires seasoning to both preserve and maintain its quality and help prevent food from sticking, this cast iron is equipped with a black matte satin interior enamel coating that’s made to resist cracking, chipping, and staining. —Alicia Geigel, Southern Living, 10 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