1ADJ-GRADED [usually ADJ n]不能穿过的;刺不进的;透不过的 If you describe something such as a barrier or a forest as impenetrable, you mean that it is impossible or very difficult to get through. 不能穿过的;刺不进的;透不过的
...the Caucasus range, an almost impenetrable barrier between Europe and Asia.
2ADJ-GRADED 费解的;难以理解的 If you describe something such as a book or a theory as impenetrable, you are emphasizing that it is impossible or very difficult to understand. 费解的;难以理解的 [emphasis]
His books are notoriously impenetrable.
他的书出了名的晦涩难懂。
...these impenetrable poems.
这些隐晦难懂的诗
impenetrably
...impenetrably detailed reports on product sales.