Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “impenetrable”


adjective    /ɪmˈpen·ɪ·trə·bəl/
impossible to enter or go through: an impenetrable jungle If language is described as impenetrable, it is impossible to understand: Too many scholarly books are written in an impenetrable jargon.
(Definition of impenetrable adjective from the Cambridge Academic Content Dictionary © Cambridge University Press)
Focus on the pronunciation of impenetrable

Definitions of “impenetrable” in other dictionaries

Word of the Day


showing a wish to help or bring advantages to others, even if it results in disadvantage for yourself

Word of the Day


Read our blog about how the English language behaves.

Learn More

New Words

Find words and meanings that have just started to be used in English, and let us know what you think of them.

Learn More