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How to pronounce impenetrable (audio)


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Dictionary definition of impenetrable

Impossible to pass through, break into, or understand, typically due to extreme density, toughness, complexity, or obscurity.
"The fortress was protected by an impenetrable wall that kept out invaders."


Detailed meaning of impenetrable

It can be used to refer to physical barriers, such as walls or fortifications, that are so strong or well-constructed that they cannot be breached or penetrated. However, it can also refer to more abstract concepts, such as ideas, arguments, or language, that are so complex or obscure that they are difficult or impossible to comprehend. For example, an impenetrable argument might be one that is so convoluted or illogical that it is impossible to follow, while an impenetrable language might be one that is spoken by only a few people and is therefore difficult for outsiders to understand. In essence, the term "impenetrable" suggests an almost insurmountable barrier, whether physical or intellectual, that is difficult or impossible to overcome.

Example sentences containing impenetrable

1. The ancient citadel's walls were practically impenetrable.
2. The intricacies of quantum physics can seem impenetrable.
3. The dense fog rendered visibility almost impenetrable.
4. The classified documents were stored in an impenetrable safe.
5. The jungle's thick foliage forms an impenetrable barrier.
6. The encryption algorithm was designed to be impenetrable.

History and etymology of impenetrable

The adjective 'impenetrable' has its etymological roots in the Latin word 'impenetrabilis,' which is formed from 'in,' meaning 'not,' and 'penetrabilis,' meaning 'able to be penetrated.' This Latin term conveyed the idea of something that cannot be passed through or entered. As it evolved into English, 'impenetrable' retained this core meaning, describing something as impossible to pass through, break into, or understand. It is often used to depict extreme density, toughness, complexity, or obscurity that makes penetration or comprehension challenging or even unachievable. The etymology of 'impenetrable' effectively encapsulates the concept of an insurmountable barrier, whether physical or metaphorical, emphasizing the formidable nature of that which cannot be easily overcome or comprehended.

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Further usage examples of impenetrable

1. The castle's defenses were virtually impenetrable.
2. The forest's underbrush is so dense, it's nearly impenetrable.
3. Her stoic demeanor seemed emotionally impenetrable.
4. The jury found the defendant's alibi impenetrable.
5. The tangle of bureaucracy made progress feel impenetrable.
6. The artist's abstract paintings can appear conceptually impenetrable.
7. The cave's darkness was so complete, it felt impenetrable.
8. The company's security protocols were designed to be impenetrable.
9. The financial world's complexity can be daunting and impenetrable.
10. The fortress's walls were fortified to be impenetrable.
11. The thorned vines created an almost impenetrable barrier.
12. The manuscript's handwriting was nearly impenetrable to decipher.
13. The detective found the suspect's alibi to be impenetrable.
14. The fog at sea made the horizon impenetrable.
15. The encryption on the file was so impenetrable that even experts couldn't crack it.
16. The dense jungle was impenetrable, making it difficult to explore.
17. His stoic expression was so impenetrable that it was hard to tell what he was thinking.
18. The lawyer's argument was so impenetrable that the judge had to ask for clarification.
19. The language barrier proved impenetrable, leaving the tourists lost and confused.
20. The fog was so thick that it created an impenetrable wall of mist.
21. The mysteries of the universe remain impenetrable to even the most brilliant minds.
22. The author's writing style was so impenetrable that many readers found the book unreadable.
23. The conspiracy theories were so impenetrable that it was impossible to separate fact from fiction.
24. The shield was impenetrable, deflecting even the strongest blows.
25. The team's defense was impenetrable, shutting down their opponents' offense.



impervious, permeable, penetrable, accessible


Prefix im-, Suffix -able, ACT 4 (American College Testing), High School 20, Protection and Avoidance

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