n. 小型单缸柱塞泵；海关检查员；肌肉抽搐

[ noun ]
someone who gives a strong sudden pull
<noun.person>

Jerker \Jerk"er\, n.
1. A beater. [Obs.] --Beau. & Fl.

2. One who jerks or moves with a jerk.

3. (Zo["o]l.) A North American river chub ({Hybopsis
biguttatus}).