I have a ball that is not bouncing back from the ground too high because it doesn't contain much rubber in it. And I also have another ball that is made either of rubber or resin of some tree. This second ball bounces back very very high. How can I describe this second ball? The ball is very "jumpy"? Or what?
Informally, you can describe the ball which bounces well as being bouncy. This is a commonly used adjective to describe it.
If you happen to need a more precise description, you can say that the ball which bounces well is very elastic, though this is less commonly used than bouncy is. And similarly the ball which does not bounce well is inelastic.
The definition of elastic to describe how well the ball bounces comes from physics, in which interactions which conserve energy are said to be elastic while interactions which lose energy are said to be inelastic. This is why elastic is a more precise, though less common, adjective to describe the bounce of a ball.