impregnable

adjective

im·​preg·​na·​ble im-ˈpreg-nə-bəl 

1

: incapable of being taken by assault : unconquerable

an impregnable fortress

2

: unassailable

also : impenetrable

impregnable walls

impregnability

(ˌ)im-ˌpreg-nə-ˈbi-lə-tē 

noun

impregnableness

im-ˈpreg-nə-bəl-nəs 

noun

impregnably

im-ˈpreg-nə-blē 

adverb

Did you know?

Impregnable is one of the many English words that bear a French ancestry, thanks to the Norman conquest of England in 1066. It derives from the Middle French verb prendre, which means "to take or capture." Combining prendre with various prefixes has given our language many other words, too, including surprise, reprise, and enterprise. Remarkably, impregnable has a different origin from the similar-looking word pregnant; that word comes from a different Latin word, praegnas, meaning "carrying a fetus."

Synonyms

• bulletproof
• indomitable
• insuperable
• insurmountable
• invincible
• invulnerable
• unbeatable
• unconquerable
• unstoppable

Examples of impregnable in a Sentence

an impregnable fortress that had foiled one invader after another over the centuries

the castle's supposedly impregnable walls

Recent Examples on the Web

There was no impregnable IP, technology, or secret Coca-Cola ingredient. —Judah Taub, Fortune, 22 Oct. 2024

Superstar Harmanpreet Kaur's unbelievable 171 not out that destroyed an impregnable Australia in a remarkable semi-final upset was seen as a turning point. —Tristan Lavalette, Forbes, 15 Oct. 2024

His party lost a majority of seats in Uttar Pradesh, India’s largest state, once considered an impregnable fortress for his brand of Hindu nationalism and identity politics. —Pratap Bhanu Mehta, Foreign Affairs, 14 June 2024

Once when told that a certain French fortress was impregnable and once when told that his mother-in-law had died. —Andrew Stuttaford, National Review, 25 Mar. 2024

Word History

Etymology

Middle English imprenable, from Middle French, from in- + prenable vulnerable to capture, from prendre to take — more at prize

First Known Use

15th century, in the meaning defined at sense 1

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Kids Definition

impregnable

adjective

im·​preg·​na·​ble im-ˈpreg-nə-bəl 

: not able to be captured by assault : unconquerable

an impregnable fortress

impregnably

-blē 

adverb