Dashpot

A dashpot is a special kind of device made of two things: a hollow cylinder with a movable piston inside, and a thick liquid like oil. When something pushes the piston, the liquid is pushed out and then it slows the piston down. It's like a car's shock absorber, which slows down the car when it hits a bump in the road. That way, the force of the bump isn't felt as much by the driver.