Something springy bounces back to its original shape after you press, squeeze, or stretch it. A trampoline is springy: when you jump on it, the surface pushes back and launches you into the air. A new sponge is springy: squeeze it tight, let go, and it pops back to full size almost instantly.

Those coiled pieces of metal in pens, mattresses, and pogo sticks compress when you push them, then snap back with force when you release the pressure. Anything that behaves this way, whether it contains actual springs or not, can be called springy.

Springy things have a kind of liveliness to them. Fresh moss on a forest floor feels springy underfoot. A dog with a springy step seems energetic and alert, almost bouncing along. New foam cushions are springy, though old, worn-out ones lose that quality and just stay compressed.

The opposite of springy would be stiff (won't compress at all) or mushy (compresses but doesn't bounce back). Springy describes that perfect quality of give and return, like a diving board or a fresh rubber ball.