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

Security must be embedded directly into the infrastructure, invisible to the customer but ironclad in practice. —Hans Kristian Aas, Forbes.com, 9 Sep. 2025

And on security, Ukraine is seeking ironclad guarantees against Russian aggression in the future, including Western peacekeeping troops on the ground. —Shane Croucher, MSNBC Newsweek, 8 Sep. 2025

Noun

The result is at once humorous and tragic: a recollection of Gardner’s soaring film career and troubled personal life, as well as a scorching indictment of the impossible constraints that actresses—burdened by moral policing and ironclad studio contracts—faced in mid-century Hollywood. —Rebecca Bihn-Wallace, Vogue, 20 Aug. 2025

Further, tech tends to get hit hard during bear markets, despite it including the biggest firms and their ironclad, fortress-like balance sheets. —Bret Kenwell, Forbes.com, 17 July 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