Simple Definition of impenetrable
: impossible to pass or see through
: impossible to understand
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>
Origin and Etymology of impenetrable
Middle English impenetrabel, from Middle French impenetrable, from Latin impenetrabilis, from in- + penetrabilis penetrable
First Known Use: 15th century
IMPENETRABLE Defined for Kids
Definition of impenetrable for Students
1 : impossible to pass through or see through <impenetrable walls> <impenetrable darkness>
2 : impossible to understand <an impenetrable mystery>
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