Dictionary

impenetrable

adjective im·pen·e·tra·ble \(ˌ)im-ˈpe-nə-trə-bəl\

: impossible to pass or see through

: impossible to understand

Full Definition of IMPENETRABLE

1
a :  incapable of being penetrated or pierced
b :  inaccessible to knowledge, reason, or sympathy :  impervious
2
:  incapable of being comprehended :  inscrutable
im·pen·e·tra·bly \-blē\ adverb

Examples of IMPENETRABLE

  1. The fort's defenses were thought to be impenetrable.
  2. <the ancient temple was surrounded by vast stretches of impenetrable jungle>

Origin of IMPENETRABLE

Middle English impenetrabel, from Middle French impenetrable, from Latin impenetrabilis, from in- + penetrabilis penetrable
First Known Use: 15th century

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