im·​pen·​e·​tra·​ble | \ (ˌ)im-ˈpe-nə-trə-bəl How to pronounce impenetrable (audio) \

Definition of impenetrable

1a : incapable of being penetrated or pierced
b : inaccessible to knowledge, reason, or sympathy : impervious
2 : incapable of being comprehended : inscrutable

Other Words from impenetrable

impenetrably \ (ˌ)im-​ˈpe-​nə-​trə-​blē How to pronounce impenetrable (audio) \ adverb

Examples of impenetrable in a Sentence

The fort's defenses were thought to be impenetrable. the ancient temple was surrounded by vast stretches of impenetrable jungle
Recent Examples on the Web The soft luster suggests, like the book, roiling tumult under beguiling but impenetrable surfaces. Inkoo Kang, Washington Post, 14 May 2022 Tokyo, like all places, is impenetrable to those who don’t take the time to learn its ways on their own terms. Daniel D'addario, Variety, 4 Apr. 2022 Infinity War and Endgame have impenetrable plot armor. Chris Smith, BGR, 4 Jan. 2022 For more than four decades that fortress has been nearly impenetrable, with the country’s national soccer team losing just two competitive matches inside its walls. Los Angeles Times, 25 Mar. 2022 In a utopian Manila in a not-too-distant future, strange rolling blackouts cast an almost impenetrable darkness over city streets. Jamie Lang, Variety, 19 Aug. 2021 Her task was made even more difficult by the fact that Maier was impenetrable, refusing to divulge information about her past to employers and acquaintances. Barbara Spindel, The Christian Science Monitor, 6 Jan. 2022 Among the few Black women who had cracked the barriers to study at one of the nation’s elite law schools, Baker attempted to find legal work in New York but met impenetrable resistance. Washington Post, 25 Feb. 2022 Its economy boomed, the dot-com bubble appeared impenetrable, and the most pressing concern among the Brits was whether the millennium bug might send fax machines into meltdown. CNN, 23 Feb. 2022 See More

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

First Known Use of impenetrable

15th century, in the meaning defined at sense 1a

History and Etymology for impenetrable

Middle English impenetrabel, from Middle French impenetrable, from Latin impenetrabilis, from in- + penetrabilis penetrable

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

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Last Updated

19 May 2022

Cite this Entry

“Impenetrable.” Dictionary, Merriam-Webster, Accessed 23 May. 2022.

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More Definitions for impenetrable


im·​pen·​e·​tra·​ble | \ im-ˈpe-nə-trə-bəl How to pronounce impenetrable (audio) \

Kids Definition of impenetrable

1 : impossible to pass through or see through impenetrable walls impenetrable darkness
2 : impossible to understand an impenetrable mystery

More from Merriam-Webster on impenetrable

Nglish: Translation of impenetrable for Spanish Speakers

Britannica English: Translation of impenetrable for Arabic Speakers


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