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

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Other Words from impregnable

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

Did You Know?

Since the days when the Norman French ruled England, English-speakers have been captured by the allure of French terms. Impregnable is one of the many English words that bear a French ancestry. 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.

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 advertising department and the newsroom have an impregnable firewall. Cheryl Hall, Dallas News, "Is your company a top workplace? Our 2020 competition is now open," 1 Mar. 2020 Yes, the defense’s performances against the three AFC Pro Bowl quarterbacks, Lamar Jackson, Deshaun Watson, and Patrick Mahomes, were far less remarkable and impregnable. Sobering stuff., "Essentially, the playoffs begin for the Patriots on Saturday. They start their Super Bowl run from a better starting point than last year.," 20 Dec. 2019 The Knicks made the Spurs’ heretofore flimsy defense appear impregnable. Jeff Mcdonald,, "For ailing Spurs, Knicks prove just the cure," 23 Nov. 2019 How to explain this remarkable career—the meteoric ascent to fame, the impregnable reputation over several decades, and then the pronounced plunge into obscurity? Robert Gottlieb, The New Yorker, "The Rise and Fall of Booth Tarkington," 4 Nov. 2019 This unparalleled excellence lies at the intersection of an impregnable defense and a risible schedule with primarily callow or incapable quarterbacks., "They rank No. 1 in total defense (238.4 yards per game), passing defense (160.4 yards per game), sacks (24), first downs allowed per game (13.2), yards allowed per play (4.07), third-down percentage (12.7 percent), and crushed spirits.," 9 Oct. 2019 After the revelations of abuse and rape, the most frightening thing the Epstein connections show is the impregnable, hermetic way class and power work in America. Adam Rogers, WIRED, "Jeffrey Epstein and the Power of Networks," 27 Aug. 2019 No system is impregnable, but North Korea’s new missiles appear designed to find one of the biggest gaps in Seoul’s armor. Simon Denyer, Washington Post, "Fast, low and hard to stop: North Korea’s missile tests crank up the threat level," 15 Aug. 2019 Ditto for the fact that the party’s onetime impregnable stronghold, Orange County, now has majority Democratic voter registration. Michael Hiltzik, Los Angeles Times, "Column: Right-wingers again demonize the tiny delta smelt to protect Big Agriculture," 12 Aug. 2019

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.

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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

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Time Traveler for impregnable

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

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Last Updated

19 Mar 2020

Cite this Entry

“Impregnable.” Dictionary, Merriam-Webster, Accessed 3 Apr. 2020.

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More Definitions for impregnable


How to pronounce impregnable (audio)

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

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