impenetrable

adjective

im·​pen·​e·​tra·​ble (ˌ)im-ˈpe-nə-trə-bəl How to pronounce impenetrable (audio)
1
a
: incapable of being penetrated or pierced
b
: inaccessible to knowledge, reason, or sympathy : impervious
2
: incapable of being comprehended : inscrutable
impenetrably 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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
This sweetly reticent follow-up is a drama about the impenetrable singularity of a young girl’s mind. Justin Chang, New Yorker, 26 May 2025 Things only get less interesting as that love triangles widens into an awkward kind of square, the chiaroscuro splendor of Soderbergh’s cinematography laboring to compensate for a murder-mystery that’s as scattered and impenetrable as Berlin itself. David Ehrlich, IndieWire, 14 Mar. 2025 Cybersecurity strategy has undergone a fundamental shift—from aspiring to build impenetrable defenses to accepting that breaches are inevitable. Tony Bradley, Forbes.com, 15 May 2025 But in person, nothing about her seems impenetrable. Thania Garcia, Variety, 9 May 2025 See All Example Sentences for impenetrable

Word History

Etymology

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

First Known Use

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

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

Browse Nearby Words

Cite this Entry

“Impenetrable.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/impenetrable. Accessed 7 Jun. 2025.

Kids Definition

impenetrable

adjective
im·​pen·​e·​tra·​ble (ˈ)im-ˈpen-ə-trə-bəl How to pronounce impenetrable (audio)
1
: impossible to get through or into
impenetrable walls
impenetrable jungle
2
: impossible to understand
an impenetrable mystery
impenetrability
(ˌ)im-ˌpen-ə-trə-ˈbil-ət-ē
noun
impenetrably adverb

More from Merriam-Webster on impenetrable

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