impenetrability
🇺🇸
/ɪmˌpenɪtrəˈbɪləti/
🇬🇧
/ɪmˌpenɪtrəˈbɪləti/
Something that cannot be entered or passed through
The forest's dense foliage created an atmosphere of impenetrability.
Something that cannot be understood
The professor's lecture was full of complex theories that added to the subject's impenetrability.