jerker
nounUK /ˈdʒɜːkə/
US /ˈdʒɜːrkər/
A jerker is a person or thing that pulls or moves something with a quick, sharp motion.
The old pump was a real jerker, shaking with every stroke.
OTHER MEANINGS
2. A machine or device that operates with a jerking motion, such as a soda jerker who serves drinks at a soda fountain.
The soda jerker mixed the fizzy drink behind the counter.
3. A tearjerker is a sad story or movie that makes people cry.
That film was a total tearjerker, and everyone left the theater crying.
4. A knee-jerker is someone who reacts quickly and automatically without thinking.
He's a knee-jerker when it comes to criticism, always answering before listening.