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Showing results for impregnable. Search instead for Imprenable.
Synonyms

impregnable

1 American  
[im-preg-nuh-buhl] / ɪmˈprɛg nə bəl /

adjective

  1. strong enough to resist or withstand attack; not to be taken by force, unconquerable.

    an impregnable fort.
    Synonyms:
    invulnerable
    Antonyms:
    vulnerable

  2. not to be overcome or overthrown.

    an impregnable argument.
    Synonyms:
    unassailable
impregnable 2 American  
[im-preg-nuh-buhl] / ɪmˈprɛg nə bəl /

adjective

  1. susceptible to impregnation, as an egg.

impregnable 1 British  
/ ɪmˈprɛɡnəbəl /

adjective

  1. unable to be broken into or taken by force

    an impregnable castle

  2. unable to be shaken or overcome

    impregnable self-confidence

  3. incapable of being refuted

    an impregnable argument
"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
impregnable 2 British  
/ ˌɪmprɛɡˈneɪtəbəl, ɪmˈprɛɡnəbəl /

adjective

  1. able to be impregnated; fertile

"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

Related Words

See invincible.

Other Word Forms

  • impregnability noun
  • impregnableness noun
  • impregnably adverb

Etymology

Origin of impregnable1

First recorded in 1400–50; late Middle English impregnable, imprenable, from Middle French, equivalent to im- im- 2 + prenable pregnable

Origin of impregnable2

impregn(ate) + -able

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Though the Cuban government has acknowledged talks, Díaz-Canel warned last month that “any act of aggression will clash with an impregnable resistance.”

From The Wall Street Journal • Apr. 3, 2026

Alcatraz island - nicknamed "the Rock" because it was regarded as an impregnable fortress - is home to the shuttered federal penitentiary that housed some of the most dangerous criminals in the US.

From BBC • Jan. 30, 2026

Once impregnable, touring sides have won more matches at the Gabba than any other Australia venue since 2021.

From BBC • Dec. 1, 2025

Singapore was considered impregnable, but it wasn’t prepared for an attack from the mainland, and its 60,000-strong garrison surrendered on Feb. 8, 1942, the worst defeat in British history.

From The Wall Street Journal • Oct. 27, 2025

If only they had an impregnable submarine like the Nautilus.

From "All the Light We Cannot See" by Anthony Doerr

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.