impregnable

¹

[im-preg-nuh-buhl]

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

[im-preg-nuh-buhl]

adjective

1. susceptible to impregnation, as an egg.

impregnable

¹

/ 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

impregnable

²

/ ˌɪmprɛɡˈneɪtəbəl, ɪmˈprɛɡnəbəl /

adjective

1. able to be impregnated; fertile

Other Word Forms

• impregnability noun
• impregnableness noun
• impregnably adverb

Word History and Origins

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

Word History and Origins

Origin of impregnable¹

C15 imprenable, from Old French, from _im- (not) + prenable able to be taken, from prendre to take

Synonym Study

See invincible.

Example Sentences

“Some criminals have understood that museums are not impregnable cultural fortresses,” said Pierre Noual, a French lawyer specializing in cultural heritage law.

Read more on The Wall Street Journal

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.

Read more on The Wall Street Journal

High-flying Crystal Palace are the only side to rival City's attacking threat, while Newcastle are living up to their name by being almost as impregnable at the back as Arsenal.

Read more on BBC

“It’s like hitting a bullet with a bullet,” someone says, crushing the naive notion of an impregnable “nuclear defense.”

Read more on Los Angeles Times

Victory would surely put them in an impregnable qualifying position, but there was a steely confidence about coach Stojkovic when he addressed the media, along with Milenkovic, here on Monday.

Read more on BBC

Related Words

• fortified 
• impenetrable 
• indestructible 
• invincible 
• invulnerable 
• unassailable