vivacity

This term describes a sparkling, high-energy quality of personality that is perceived as charming or magnetic. It differs from mere hyperactivity or loudness by implying a sense of grace, wit, and social appeal. It is almost exclusively used in a positive sense to describe someone whose presence energizes a room.

As an abstract quality, this noun is uncountable. It cannot be pluralized to describe multiple instances of liveliness; instead, it refers to a general state of being. To quantify it, one must use partitive constructions such as a streak of vivacity or a burst of vivacity.