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

The core bargain in the framework would have entailed Ukraine embracing permanent neutrality, foreclosing its possible membership in NATO, in return for ironclad security guarantees. —Samuel Charap, Foreign Affairs, 8 May 2025

For example, the Nazi past has led Germany both to an ironclad support of Israel and a strong aversion to war in general. —Mark Sappenfield, Christian Science Monitor, 2 May 2025

Noun

Comments An ironclad rule in moviemaking is that only the director gets to call cut. —Jordan Hoffman, EW.com, 8 May 2025

The movie’s universe has its own specific set of ironclad rules and that’s all that matters. —Katie Walsh, Los Angeles Times, 26 Apr. 2025

Word History

First Known Use

Adjective

circa 1847, in the meaning defined at sense 1

Noun

1862, in the meaning defined above

Rhymes for ironclad

• cephalad
• galahad
• libertad
• undergrad
• ad
• add
• bad
• brad
• cad
• clad
• dad
• fad

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