im·​preg·​na·​ble | \ im-ˈpreg-nə-bəl How to pronounce impregnable (audio) \

Definition of impregnable

1 : incapable of being taken by assault : unconquerable an impregnable fortress
2 : unassailable also : impenetrable impregnable walls

Other Words from impregnable

impregnability \ (ˌ)im-​ˌpreg-​nə-​ˈbi-​lə-​tē How to pronounce impregnable (audio) \ noun
impregnableness \ im-​ˈpreg-​nə-​bəl-​nəs How to pronounce impregnable (audio) \ noun
impregnably \ im-​ˈpreg-​nə-​blē How to pronounce impregnable (audio) \ 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."

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 The conservative bloc of that era was not impregnable, however. Michael Hiltzik, Los Angeles Times, 17 Dec. 2021 Yet Sarita has an impregnable virtue that belies her horrifying plight. Boyd Tonkin, WSJ, 22 Oct. 2021 Camp Randall Stadium wasn’t always a fortress impregnable to Michigan football. Ryan Ford, Detroit Free Press, 3 Oct. 2021 The small portable submarine could shuttle between boat and land, and was also impregnable should pirates attack the vessel. Mark Ellwood, Robb Report, 1 Sep. 2021 The idea of white female beauty as the impregnable standard in Western art is only one of the questions raised by this endlessly evocative painting. The New Yorker, 2 Aug. 2021 The most significant confrontation this week has come in Mazar-e Sharif, the country’s fourth-largest city and the capital of Balkh province, long impregnable to Taliban threats. Washington Post, 22 June 2021 Montefeltro, a wealthy mercenary—who at the age of 15 had seized a fortress long believed impregnable—was also a bookish man, like many in the Renaissance. Ernest Hilbert, WSJ, 23 Apr. 2021 The health crisis that peaked last month in India demonstrated the dangers of contagious new virus variants; a recent smaller surge in Taiwan showed that even seemingly impregnable places could see their strategies collapse. Washington Post, 4 June 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'impregnable.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of impregnable

15th century, in the meaning defined at sense 1

History and Etymology for impregnable

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

Learn More About impregnable

Time Traveler for impregnable

Time Traveler

The first known use of impregnable was in the 15th century

See more words from the same century

Listen to Our Podcast About impregnable

Dictionary Entries Near impregnable




See More Nearby Entries 

Statistics for impregnable

Last Updated

21 Dec 2021

Cite this Entry

“Impregnable.” Dictionary, Merriam-Webster, Accessed 20 Jan. 2022.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

More Definitions for impregnable



English Language Learners Definition of impregnable

: not able to be captured by attack : very strong
: not likely to be weakened or changed


im·​preg·​na·​ble | \ im-ˈpreg-nə-bəl How to pronounce impregnable (audio) \

Kids Definition of impregnable

: not able to be captured by attack : unconquerable

More from Merriam-Webster on impregnable

Nglish: Translation of impregnable for Spanish Speakers

Britannica English: Translation of impregnable for Arabic Speakers


Test Your Vocabulary

Name that Thing: Flower Edition

True or False

Test your knowledge - and maybe learn something along the way.

Universal Daily Crossword

A daily challenge for crossword fanatics.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!