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iron·​clad ˈī(-ə)rn-ˈklad How to pronounce ironclad (audio)
: sheathed in iron armor
used especially of naval vessels
: so firm or secure as to be unbreakable: such as
: binding
an ironclad oath
: having no obvious weakness
an ironclad case against the defendant


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iron·​clad ˈī(-ə)rn-ˌklad How to pronounce ironclad (audio)
: an armored naval vessel especially of the mid to late 19th century

Example Sentences

Adjective The company has an ironclad policy against revealing secrets to competitors. He has an ironclad alibi.
Recent Examples on the Web
The logic behind Tár’s collapse, in the end, is ironclad. Spencer Kornhaber, The Atlantic, 19 Nov. 2022 Though Trump remains the central animating force within the GOP, the former president's down-ticket potency is decidedly less ironclad after Tuesday night. Rafi Schwartz, The Week, 8 Nov. 2022 But even seemingly ironclad responses don't always hold up. Will Weissert, ajc, 26 Oct. 2022 Though the city’s myriad hot dog vendors take their liberties here and there, swapping regular relish for neon or a green tomato for a red one, one rule is ironclad: no ketchup. Talia Soglin, Chicago Tribune, 21 Oct. 2022 The Hollywood studio system that had an ironclad hold over its stars since the 1930s was already in a period of decline, its control slowly being eroded by the loss of exhibition thanks to the Paramount Decrees and other economic factors. Maureen Lee Lenker,, 28 Sep. 2022 Toledo sprang from the passion of childhood friends Dan Álvarez de Toledo and Jordan Dunn-Pilz, who grew up busking in the coastal town of Newburyport, Mass., and developed an ironclad relationship through music. Beau Hayhoe, SPIN, 23 Sep. 2022 Whereas Browns quarterback Jacoby Brissett faces an ironclad Steelers pass defense, Chubb gets a paper-thin Pittsburgh rushing defense. Nick Hennion, Chicago Tribune, 22 Sep. 2022 In an era of ironclad segregation, Milwaukee’s Bronzeville grew into a vibrant and self-sufficient business and cultural community, renowned for its nightlife and entertainment. David D. Haynes, Journal Sentinel, 6 Aug. 2022
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 See More

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.

Word History

First Known Use


circa 1847, in the meaning defined at sense 1


1862, in the meaning defined above

Time Traveler
The first known use of ironclad was circa 1847

Dictionary Entries Near ironclad

Cite this Entry

“Ironclad.” Dictionary, Merriam-Webster, Accessed 6 Dec. 2022.

Kids Definition

ironclad 1 of 2


iron·​clad -ˈklad How to pronounce ironclad (audio)
: covered by iron armor
: rigorous sense 1, exacting
ironclad laws


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iron·​clad -ˌklad How to pronounce ironclad (audio)
: an armored naval vessel
Last Updated: - Updated example sentences
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