knocking 

英汉解释

n. 爆震音；卡答卡答的故障声音
v. 敲（knock的ing形式）

同义词

n. knock

参考例句

1. The medicine is effective for knocking colds.
这种药祛除感冒很有效。
2. Affected vehicles usually emit a knocking sound while in motion.
受影响的车辆通常发出敲击声，而在动议。
3. Why not try knocking at the back door, even if nobody hears you at the front door.
即使前门没人听到，为什么不试试敲敲后门。（实验，试一试某种方法）。

英英解释

n.
  1. the sound of knocking (as on a door or in an engine or bearing)

网络释义

knocking
爆震; 爆振; 爆震音; 爆震声;
Abnormal knocking
异响;
Door Knocking
上门询问求职;
Engine knocking
引擎爆震; 爆震; 敲缸;
Knocking Sensor
爆震感知器; 爆振传感器;