impenetrable
adjective
im·pen·e·tra·ble
(ˌ)im-ˈpe-nə-trə-bəl 
1
a
: incapable of being penetrated or pierced
b
: inaccessible to knowledge, reason, or sympathy : impervious
2
: incapable of being comprehended : inscrutable
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
Most of those minerals are currently buried beneath thick sheets of previously impenetrable ice.
—
Mack Degeurin, Popular Science, 10 Apr. 2025
Image Border The Wall The most memorable promise that Mr. Trump made on the campaign trail was to erect an impenetrable barrier along the entire southern border, which is almost 2,000 miles, and to have Mexico pay for it.
—Miriam Jordan, New York Times, 18 Jan. 2025
Even more impressively, against a Colorado defense that was impenetrable Saturday, with the Rays lacing the balls all over the field and the Rockies making a reel of highlight plays.
—Marc Topkin, The Orlando Sentinel, 30 Mar. 2025
The difficult terrain, impenetrable vegetation, and challenging navigation mean most hikers cover at least 50 percent more distance than that.
—Alex Hutchinson, Outside Online, 25 Mar. 2025
See All Example Sentences for impenetrable
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Mack Degeurin, Popular Science, 10 Apr. 2025
Image Border The Wall The most memorable promise that Mr. Trump made on the campaign trail was to erect an impenetrable barrier along the entire southern border, which is almost 2,000 miles, and to have Mexico pay for it.
—Miriam Jordan, New York Times, 18 Jan. 2025
Even more impressively, against a Colorado defense that was impenetrable Saturday, with the Rays lacing the balls all over the field and the Rockies making a reel of highlight plays.
—Marc Topkin, The Orlando Sentinel, 30 Mar. 2025
The difficult terrain, impenetrable vegetation, and challenging navigation mean most hikers cover at least 50 percent more distance than that.
—Alex Hutchinson, Outside Online, 25 Mar. 2025
See All Example Sentences for impenetrable
Cite this Entry
“Impenetrable.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/impenetrable. Accessed 29 Apr. 2025.
Copy CitationKids Definition
impenetrable
adjective
im·pen·e·tra·ble
(ˈ)im-ˈpen-ə-trə-bəl
1
: impossible to get through or into
impenetrable walls
impenetrable jungle
2
: impossible to understand
an impenetrable mystery
impenetrability
noun
(ˌ)im-ˌpen-ə-trə-ˈbil-ət-ē
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