impenetrable

adjective
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

Keep scrolling for more

Other Words from impenetrable

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

Another factor is the nearly impenetrable landscape, known as valley thicket. New York Times, "Where Female Elephants Without Tusks Roam — and Poachers Stay Away," 16 June 2018 But the effect of the deployment has been felt most significantly among undocumented migrants, who now see a more impenetrable Mexico. New York Times, "Mexico’s Crackdown at Its Southern Border, Prompted by Trump, Scares Migrants From Crossing," 24 June 2019 The basement was engulfed in a black, impenetrable fog. Deanna Pan, BostonGlobe.com, "‘I can’t be naive anymore’: Targeted by arson fires, Mass. rabbis face anti-Semitism at home," 24 June 2019 The somewhat impenetrable process by which regions assign housing targets to municipalities tends to leave larger cities holding the rope; small, wealthy suburban communities often have laughably low targets. James Sutton, National Review, "The California Housing Crisis and the Problem with Local Control," 19 June 2019 Through it all, Fails maintains a serene and poignant presence, skateboarding from situation to situation with (usually) impenetrable calm. The Washington Post, The Mercury News, "Review: ‘Last Black Man’ is a lyrical, beautiful ode to loss," 13 June 2019 An earth mother with an impenetrable aura of self-containment, she’s been deeply traumatized by her direct involvement in Perry’s death and her inability to share what happened with her husband and daughter. Sophie Gilbert, The Atlantic, "The Family Values of Big Little Lies," 7 June 2019 In contrast, when the first design of the Obama Center was unveiled last year, its museum tower was widely panned as an impenetrable monolith. Blair Kamin, chicagotribune.com, "The message of material: How the Obama Center gets built looms large," 18 May 2018 New York City’s $32 million effort to reduce its rat population includes reducing their food supply with impenetrable garbage cans and smoking them out of their burrows with dry ice. Katie Honan, WSJ, "New City Rat Controls Put a Chill on Population Growth," 6 Apr. 2019

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.

See More

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

Keep scrolling for more

Learn More about impenetrable

Statistics for impenetrable

Last Updated

12 Jul 2019

Look-up Popularity

Time Traveler for impenetrable

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

See more words from the same century

Keep scrolling for more

More Definitions for impenetrable

impenetrable

adjective

English Language Learners Definition of impenetrable

: impossible to pass or see through
: impossible to understand

impenetrable

adjective
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

Keep scrolling for more

Comments on impenetrable

What made you want to look up impenetrable? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

to form ideas or theories about something

Get Word of the Day daily email!

Test Your Vocabulary

Farm Idioms Quiz

  • cow coming home
  • What does 'poke' refer to in the expression 'pig in a poke'?
Name That Thing

Test your visual vocabulary with our 10-question challenge!

TAKE THE QUIZ
SCRABBLE® Sprint

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ
Love words? Need even more definitions?

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