overflowing with vitality; exuberant; effervescent
Describes a person, atmosphere, or group that is brimming with energy and lively spirits. Often used in written or slightly formal contexts.
The audience was captivated by his speech overflowing with vitality.
The new employees' exuberant demeanor brightened up the workplace.
A four-character compound (yojijukugo) combining 活気 (vitality) and 横溢 (overflowing). The exact origin is uncertain, but it follows a common pattern of Sino-Japanese compounds.