Ebullient
Etymology
From Latin ebullire, "to bubble up," from e-, "out," and bullire, "to boil" (the source of "boil" itself). It first meant literally boiling or bubbling, then shifted to describe feelings that seem to boil over. Today the physical sense is nearly gone, but the image survives: joy that froths up like a boiling liquid.
adjective · /ih-BUHL-yunt/
Overflowing with cheerful, enthusiastic energy.
What it names
A high-spirited exuberance that bubbles up and spills over, too lively to be contained.
Example
She returned from the trip ebullient, talking over everyone in her rush to describe it all.
Related idea
Exuberant is close, but ebullient specifically carries the bubbling-over image and a sense of buoyant, effervescent high spirits.