The adjective "bouncy" means full of energy, lively and animated. It can also refer to something that is springy or elastic in nature, such as a bouncy castle or mattress.
Usage examples
The children had a fantastic time playing on the bouncy castle at the birthday party.
The puppy's tail was wagging so fast that it looked bouncy.
She chose to wear a bouncy, curly hairstyle for her friend's wedding.
The basketball had a lot of bounce, making it very bouncy on the court.
The trampoline made her feel light and bouncy as she jumped higher and higher.
The bouncy music at the party got everyone up and dancing.
The energetic toddler couldn't sit still and was constantly bouncing around, full of bouncy energy.
The gymnast performed an amazing series of bouncy flips and jumps on the springy mat.
The beach ball was filled with air, making it bouncy enough to play games with at the seaside.
The spring in his step made him feel youthful and bouncy, despite his old age.
(Note that some experts have warned against babies sleeping in bouncy seats unsupervised, though I will admit to having let my middle child sleep in one out of desperation before I got a Rock «n Play.) (exclusivepumping.com)
In this case the expected risk of injury associated with bouncy castles was not a risk of serious harm, as in fact, tragically, arose.» (newlawjournal.co.uk)
The Boppy Noggin Nest Head Support (full review here) is another really popular product and works really well in bouncy seats and swings. (babyflathead.org)