1. impossible to change, break, or dispute; completely secure or certain
2. covered or protected with iron armor
Usage: historical

1. a warship covered with iron armor plates
Usage: historical

Examples

• The contract contained an ironclad guarantee of full refund.
• She had ironclad proof that he was lying.
• The witness provided an ironclad alibi for the defendant.
• The ironclad ships revolutionized naval warfare in the 1860s.
• The USS Monitor was a famous Civil War ironclad.
• His ironclad determination helped him succeed despite obstacles.
• The agreement includes ironclad provisions to protect both parties.