[adjective ahy-ern-klad; noun ahy-ern-klad]


covered or cased with iron plates, as a ship for naval warfare; armor-plated.
very rigid or exacting; inflexible; unbreakable: an ironclad contract.


a wooden warship of the middle or late 19th century having iron or steel armor plating.

Origin of ironclad

First recorded in 1850–55; iron + clad1 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for ironclad

Contemporary Examples of ironclad

Historical Examples of ironclad

  • First of all I'd have to tie Josephine Francis down with an ironclad contract.

  • You might go so far as t' give that bellerin' ironclad a toot.'

  • The ironclad seemed to rebound and tremble for a moment, and then passed on.

    The Lively Poll

    R.M. Ballantyne

  • The vessel described was the Miantonoma, an American ironclad turret-ship.

    Man on the Ocean

    R.M. Ballantyne

  • A monster Russian ironclad, it was said, lay somewhere “outside.”

British Dictionary definitions for ironclad


adjective (ˌaɪənˈklæd)

covered or protected with ironan ironclad warship
inflexible; rigidan ironclad rule
not able to be assailed or contradictedan ironclad argument

noun (ˈaɪənˌklæd)

a large wooden 19th-century warship with armoured plating
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for ironclad

1852, of warships, American English, from iron (n.) + clad. Of contracts, etc., 1884. As a noun meaning "iron-clad ship," it is attested from 1862.

Online Etymology Dictionary, © 2010 Douglas Harper