a.

1. 不纯净的；脏的
   The air of a big city is often impure.

   大城市的空气往往是污浊的。

2. 不纯的，搀假的
   an impure chemical

   不纯的化学物

3. 不纯洁的；不道德的；淫猥的
   impure thoughts

   坏念头

4. 渎神的
5. （颜色、式样、音调等）混杂的
6. 【语】不纯的（指语言中夹杂外国用法或带有语法错误等）

adj.

1. mixed with foreign matter; adulterated or tainted.
2. morally wrong, especially in sexual matters.
   ▸defiled or contaminated according to ritual prescriptions.