bouncy
adj.able to spring back into shape after being squeezed or hit. It also describes someone who has a lot of energy and seems very happy.
adj.capable of returning to an original shape after compression; resilient. When applied to people or music, it describes a lively, energetic, and cheerful quality.
“The children love playing on the bouncy castle.”
“The new mattress is quite bouncy, which might take some time to get used to if you prefer a firm bed.”
“Her bouncy personality and relentless optimism made her the natural choice for leading the team through the difficult transition period.”
Often used predicatively after linking verbs like 'feel' or 'seem' to describe a person's mood.
From bounce + -y.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.