ironclad

1 of 2

adjective

iron·​clad ˈī(-ə)rn-ˈklad 

1

: sheathed in iron armor

—used especially of naval vessels

2

: so firm or secure as to be unbreakable: such as

a

: binding

an ironclad oath

b

: having no obvious weakness

an ironclad case against the defendant

ironclad

2 of 2

noun

iron·​clad ˈī(-ə)rn-ˌklad 

: an armored naval vessel especially of the mid to late 19th century

Examples of ironclad in a Sentence

Adjective

The company has an ironclad policy against revealing secrets to competitors.

He has an ironclad alibi.

Recent Examples on the Web

Adjective

But as University of Western Ontario’s Paul Wiegert points out in his new study published in The Planetary Science Journal, these conclusions remain ironclad only so long as nothing influences its path. —Andrew Paul, Popular Science, 12 Sep. 2024

But as anyone who follows real-life celebrity news might expect, Margaret is only giving each of them little pieces of her story and there's an ironclad NDA keeping them from sharing the deets. —Bailey Richards, People.com, 16 Oct. 2024

Noun

Organizations will be able to extract valuable insights from sensitive information without exposing the underlying data, opening up unprecedented opportunities for cross-industry collaboration while maintaining ironclad security. —Bernard Marr, Forbes, 30 Oct. 2024

This action underscores the United States’ ironclad commitment to the defense of Israel, and to defend Americans in Israel, from any further ballistic missile attacks by Iran. —Anders Hagstrom, Fox News, 15 Oct. 2024

Word History

First Known Use

Adjective

circa 1847, in the meaning defined at sense 1

Noun

1862, in the meaning defined above

Kids Definition

ironclad

1 of 2 adjective

iron·​clad -ˈklad 

1

: covered by iron armor

2

: rigorous sense 1, exacting

ironclad laws

ironclad

2 of 2 noun

iron·​clad -ˌklad 

: an armored naval vessel