opaque

1. ADJ If an object or substance is opaque, you cannot see through it. 不透明的

You can always use opaque glass if you need to block a street view. 如果你需要擋住外面的街景，你隨時可以使用不透明玻璃。

2. ADJ If you say that something is opaque, you mean that it is difficult to understand. 難理解的

...the opaque language of the inspector's reports. …檢查員報告中晦澀難懂的語言。