im·pen·e·tra·ble 
/ɪmˈpɛnətrəbəl/ adjective
/ɪmˈpɛnətrəbəl/ adjective [more impenetrable; most impenetrable] 1 : impossible to pass or see through
▪ an impenetrable wall/barrier/jungle ▪ The fort's defenses were thought to be impenetrable. ▪ impenetrable darkness/fog 2 : impossible to understand
▪ an impenetrable mystery ▪ an impenetrable secret code
▪ an impenetrable wall/barrier/jungle ▪ The fort's defenses were thought to be impenetrable. ▪ impenetrable darkness/fog
▪ an impenetrable mystery ▪ an impenetrable secret code
— im·pen·e·tra·bil·i·ty /ɪmˌpɛnətrəˈbɪləti/ noun [noncount]
/ɪmˌpɛnətrəˈbɪləti/ noun [noncount]— im·pen·e·tra·bly /ɪmˈpɛnətrəbli/ adverb
▪ an impenetrably complex mystery ▪ an impenetrably thick wall
/ɪmˈpɛnətrəbli/ adverb ▪ an impenetrably complex mystery ▪ an impenetrably thick wall
