iron·​clad | \ ˈī(-ə)rn-ˈklad How to pronounce ironclad (audio) \

Definition of ironclad

 (Entry 1 of 2)

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


iron·​clad | \ ˈī(-ə)rn-ˌklad How to pronounce ironclad (audio) \

Definition of ironclad (Entry 2 of 2)

: 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 However, a cadre of notable Republicans launched unofficial campaigns months ago with promises of loosening the Democrats’ ironclad grip on California’s state government. Los Angeles Times, 2 July 2021 While medieval knights might have correlated honor to conquering, slaying, and adherence to chivalric code, the Western world’s once-ironclad mores have morphed into new social pressures. Tyler Bey, The Christian Science Monitor, 30 July 2021 Finally, the third possibility is that McConnell does have ironclad control of his caucus, and the cloture vote will fail, and this whole song-and-dance is just another legislative delusion. Michael Tomasky, The New Republic, 26 July 2021 His mother, whose family had fled the Delta three decades earlier, had tried to prepare him for the unwritten but ironclad rules that would govern his time in Mississippi. Wright Thompson, The Atlantic, 22 July 2021 Walz should get an ironclad agreement that that session will not be used to force out additional commissioners. Editorial Board, Star Tribune, 8 July 2021 Justice Alito wrote that the court was not announcing an ironclad standard for lower courts to apply in cases challenging voting restrictions. New York Times, 1 July 2021 Apple’s ironclad control over the App Store is already under investigation by regulators and lawmakers in Europe and the U.S. NBC News, 21 May 2021 During his trip, Secretary Blinken will meet with Israeli leaders about our ironclad commitment to Israel’s security. Tyler Olson, Fox News, 26 May 2021 Recent Examples on the Web: Noun During the Civil War, Eads won a contract to build Union ironclads. Mike Scott,, 1 May 2018 In 1862, during the Civil War, the ironclads USS Monitor and CSS Virginia (formerly USS Merrimac) clashed for five hours to a draw at Hampton Roads, Va., 9 Mar. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'ironclad.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of ironclad


circa 1847, in the meaning defined at sense 1


1862, in the meaning defined above

Keep scrolling for more

Learn More About ironclad

Time Traveler for ironclad

Time Traveler

The first known use of ironclad was circa 1847

See more words from the same year

Dictionary Entries Near ironclad

iron chloride


iron curtain

See More Nearby Entries 

Statistics for ironclad

Last Updated

17 Sep 2021

Cite this Entry

“Ironclad.” Dictionary, Merriam-Webster, Accessed 18 Sep. 2021.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

Keep scrolling for more

More Definitions for ironclad



English Language Learners Definition of ironclad

: not able to be changed
: too strong to be doubted or questioned


Test Your Vocabulary

Dog Words Quiz

  • shiba puppy more or less demanding cuddles
  • Which of the following animals has a dog in its etymology?
True or False

Test your knowledge - and maybe learn something along the way.


Anagram puzzles meet word search.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!