ebullient
The communities they built reflected the ebulliency of the people who founded them.
The scientists had the ebulliency of people who had discovered something new and exciting.
He spoke with the infectious ebulliency of youth.
She has an ebulliency of spirit that is immediately attractive.

SMART Vocabulary: related words and phrases

Excitement, interest, energy and enthusiasm
alacrity
animation
ardour
avidity
boosterism
commotion
frenzy
friskiness
frisson
frolic
get a buzz out of something/doing something
get-up-and-go
hubbub
pep
perkiness
physicality
piquancy
pizzazz
whirl
zealousness