Answer: ironclads

AnswerCrossword Clue
IRONCLADSOld warships
IRONCLADSCivil War combatants
IRONCLADSCivil War ships
ironcladsIRONCLAD, an armored warship
ironcladswooden warship of the middle or late 19th century having iron or steel armor plating
ironcladscovered or cased with iron plates, as a ship for naval warfare; armor-plated
ironcladsvery rigid or exacting; inflexible; unbreakable