If a person or their expression is inscrutable, it is very hard to know what they are really thinking or what they mean.
例句
In public he remained inscrutable.在公開場合他一直像一個謎。
英漢詞典釋義
adj.
不可理解的;謎一樣的
an inscrutable smile不可思議的微笑an inscrutable fog不能透視的霧
英英詞典釋義
Adjective
1. of an obscure nature;
"the new insurance policy is written without cryptic or mysterious terms""a deep dark secret""the inscrutible workings of Providence""in its mysterious past it encompasses all the dim origins of life"- Rachel Carson"rituals totally mystifying to visitors from other lands"