Definitions

1. noun

A warship with a hull made of iron or steel, especially one of the 19th century.

“The ironclad was a significant development in naval warfare during the American Civil War.”

2. adjective

Completely secure or guaranteed, especially by law or a formal agreement.

“The court’s decision was seen as ironclad evidence of the company’s guilt.”

3. adjective

Completely waterproof or airtight.

“The ironclad bag kept the camera dry in the rain.”