impenetrable

[im-pen-i-truh-buhl]

adjective

1. not penetrable; that cannot be penetrated, pierced, entered, etc.

2. inaccessible to ideas, influences, etc.

3. incapable of being understood; inscrutable; unfathomable.

   an impenetrable mystery.

   Synonyms: hidden, obscure, mysterious, incomprehensible
   Antonyms: lucid, clear

4. Physics.,  possessing impenetrability.

impenetrable

/ ɪmˈpɛnɪtrəbəl /

adjective

1. incapable of being pierced through or penetrated

   an impenetrable forest

2. incapable of being understood; incomprehensible

   impenetrable jargon

3. incapable of being seen through

   impenetrable gloom

4. not susceptible to ideas, influence, etc

   impenetrable ignorance

5. physics (of a body) incapable of occupying the same space as another body

Other Word Forms

• impenetrableness noun
• impenetrably adverb
• impenetrability noun

Word History and Origins

Origin of impenetrable¹

1425–75; late Middle English impenetrabel < Latin impenetrābilis. See im- ², penetrable

Example Sentences

Contributing factors include the stress of living in a world that’s sensorially overwhelming or socially impenetrable.

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Contributing factors include the stress of living in a world that’s sensorially overwhelming or socially impenetrable.

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“This is why I kept this thing in a case. I put a slew of enchantments over it, which was supposed to make the trophy case impenetrable!”

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It soon rendered fields impossible to plough, as lines of the goblet-shaped bushes, many of them three feet across, formed impenetrable natural fences in the paths of tractors.

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He dove deep into impenetrable environmental impact documents.

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Related Words

• arcane 
• baffling 
• inexplicable 
• inscrutable 
• mysterious 
• unaccountable 
• unfathomable 
• unintelligible