There's an indefinable air of tension in this town. 這城鎮里有種難以描述的緊張氣氛。
The vision leaves an indefinable longing and regret. 這種景象留給人們一種莫名的渴望和遺憾。
And she had something extra, something indefinable. 她還有一些別的事，一些不能確定的事。
The Cold War came to an end unexpectedly, and America's opponents became so indefinable that it was difficult to define its national interests. 摘要冷戰的結束不期而至，美國的對手變得難以確定，其國家利益也難以界定。