ironclad

American  

[ahy-ern-klad, ahy-ern-klad] / ˈaɪ ərnˈklæd, ˈaɪ ərnˌklæd /

adjective

1. covered or cased with iron plates, as a ship for naval warfare; armor-plated.

2. very rigid or exacting; inflexible; unbreakable.

   an ironclad contract.

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noun

1. a wooden warship of the middle or late 19th century having iron or steel armor plating.

ironclad British  

adjective

1. covered or protected with iron

   an ironclad warship

2. inflexible; rigid

   an ironclad rule

3. not able to be assailed or contradicted

   an ironclad argument

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noun

1. a large wooden 19th-century warship with armoured plating

Etymology

Origin of ironclad

First recorded in 1850–55; iron + clad ¹

Example Sentences

Nvidia’s next earnings report in November made it clear the $100 billion figure wasn’t exactly an ironclad commitment.

From MarketWatch • Feb. 1, 2026

So oil companies who go in need to have ironclad legal terms that aren’t just about a change of control in Venezuela.

From Barron's • Jan. 7, 2026

Its defense agreement fell short of the ironclad mutual-defense pact it wants.

From The Wall Street Journal • Nov. 21, 2025

The whole idea is that they are likelier to win the battle for public opinion, and thus the legislative fight, if their argument is clear, ironclad, impossible to refute.

From Slate • Oct. 1, 2025

“You would’ve made a great bhabhi someday,” he said, and that, more than anything, drove it all home with an ironclad finality.

From "When Dimple Met Rishi" by Sandhya Menon

Related Words

• abiding
• definite
• inflexible
• unwavering