I was reading about gravity assist.
This maneuver is sometimes called a gravitational slingshot. But to me it seems more like a sling (like the one the Biblical David used against Goliath) The maneuver makes use of the movement of the planet (like a sling makes use of the movement of the hand) and the orbit is curved, like that of a sling. I don't immediately think of a slingshot when I read about it.
A slingshot (Y-bow) is stationary. A gravitational "slingshot" would never work if the planet was stationary.
OK, it is a detail, but technical terms are often very precise. Why is this term used? (Or did I miss something and it is not misleading?) (I am interested in the exchange of energy between bodies so my question is not only linguistic.)