The noun exuberance means the quality of being full of energy or the behaviour of someone who feels this way.
Synonyms are eagerness, excitement, high spirits, or vigor.
The word origins from French (16th century) exubérance meaning “an overflowing”, and from Late Latin exuberant meaning “superabundance”, the abstract noun from exuberant meaning “be abundant, grow luxuriously”. In English, the figurative meaning “joy, happiness” is attested from 1610s.
He has a sense of youthful exuberance despite his age.
The team leaders admired Erik’s exuberance at work.
The exuberance of my dog can scare the kids in the park.