Definition of "ironclad" []

• Sheathed with iron plates for protection. (adjective)
• Rigid; fixed: an ironclad rule. (adjective)
• A 19th-century warship having sides armored with metal plates. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• ""Unfortunately the word ironclad is a bit of a myth," says divorce lawyer Clifford M. Solomon, partner of Solomon Tanenbaum in Westchester."
• "“When a Grumley give his word, his word is ironclad.”"
• "The Confederates were fully aware of this, and as soon as they could, placed on the waters of their rivers and harbors vessels new to naval warfare, called ironclad rams."