ironclad

[ahy-ern-klad, ahy-ern-klad]

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.

noun

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

ironclad

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

noun

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

Word History and Origins

Origin of ironclad¹

First recorded in 1850–55; iron + clad ¹

Example Sentences

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

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Then, in 1973, a team of scientists from Duke University’s Maritime Laboratory found the historic ironclad.

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Funds that invest in AI deals say they carry little risk, because tech companies with deep pockets have ironclad leases that will generate the money to pay investors back.

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“We have an ironclad rule at IMAX, which is that our word is our word and we won’t mess around with that,” the CEO said.

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But I am less sure about his claim that, because of a growing 19th-century population, “land’s connection to power became ironclad.”

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Related Words

• abiding 
• definite 
• inflexible 
• unwavering