enliven

This term describes the act of injecting vitality or spirit into a stagnant situation or a lethargic person. It carries a positive, refreshing connotation, suggesting a transition from boredom or sadness to a state of engagement and brightness. It is frequently used in social contexts to describe the improvement of an atmosphere.

While similar to words like stimulate or excite, it specifically implies a brightening effect, often through the addition of something pleasant or surprising. It is more formal than make lively but less clinical than revitalize.