means Describing something that bounces back into shape after being pressed, bent, or stretched — elastic and bouncy.

from From 'spring,' the Old English 'springan,' to leap or burst forth — the same word that names both the season when life leaps up from the ground and the coiled metal that leaps back when you let go. The '-y' is the plain old English suffix meaning 'having the quality of,' so 'springy' is simply 'spring-like': full of leap.