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
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
Alicia Adamczyk, Fortune, 27 June 2025
Two Coalitions, One Law of Unintended Escalation The strikes revealed an arena ruled by coalitions of convenience, not ironclad alliances.
—Guney Yildiz, Forbes.com, 24 June 2025
Samantha Bergeson, IndieWire, 13 June 2025
With Republicans squabbling over key provisions, Trump for the first time eased up on his previous ironclad demand that lawmakers get the bill to his desk by the Independence Day holiday.
—Dave Goldiner, New York Daily News, 27 June 2025
See All Example Sentences for ironclad
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Adjective
The event is the culmination of a monthslong production by wedding planners and, very likely, by teams of lawyers who have combed through the couple’s complex finances to create an ironclad prenuptial agreement.
—Alicia Adamczyk, Fortune, 27 June 2025
Two Coalitions, One Law of Unintended Escalation The strikes revealed an arena ruled by coalitions of convenience, not ironclad alliances.
—Guney Yildiz, Forbes.com, 24 June 2025
Noun
Yet when a message arrives from a potential client (Lily James) who needs his protection just to stay alive, Ahmed’s character abandons his own ironclad rules of communication.
—Samantha Bergeson, IndieWire, 13 June 2025
With Republicans squabbling over key provisions, Trump for the first time eased up on his previous ironclad demand that lawmakers get the bill to his desk by the Independence Day holiday.
—Dave Goldiner, New York Daily News, 27 June 2025
See All Example Sentences for ironclad
Cite this Entry
“Ironclad.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ironclad. Accessed 20 Jul. 2025.
Copy CitationKids 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
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