mid-15c., from Middle French impenetrable, from Latin impenetrabilis "that cannot be penetrated," from assimilated form of in- "not, opposite of" (see in- (1)) + penetrabilis "penetrable" (see penetrate). Related: Impenetrably; impenetrability.
例文
1. Their jargon is impenetrable to an outsider.
彼らの言葉は他人には分からない。
2.I find his style somewhat impenetrable .
私は彼の行動様式が非常に理解できないことを発見した。
3.The language of this document would be impenetrable to anyone except a specialist.
このファイルは専門家以外の誰にも読めない。
4.His bookare notoriously impenetrable .
彼の本は難解で難解な名前を出している。/
5.Still,I had also judged the jungle of both banks quite impenetrable .