say it: AHY-urn-klad
ironclad is an adjective and noun meaning "sheathed in iron plates for protection". It carries 3 recorded senses.
sheathed in iron plates for protection
inflexibly entrenched and unchangeable
“brassbound traditions”
“brassbound party loyalists”
“an ironclad rule”
a wooden warship of the 19th century that is plated with iron or steel armor
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for ironclad come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.