vivacity

noun

1. (countable, uncountable)The quality or state of being vivacious.

   “But reposed natures may do well in youth. […] On the other side, heat and vivacity in age, is an excellent composition for business.”

   “The one entertained me with her vivacity when I was gay, the other with her sense when I was serious.”

   “In the name of truth and common sense, why should not one woman acknowledge that she can take more exercise than another? or, in other words, that she has a sound constitution; and why to damp innocent vivacity, is she darkly to be told, that men will draw conclusions which she little thinks of?”

   “Some secret sorrow, or the brooding spirit of some moody passion, had quenched the light and ingenuous vivacity of youth in a countenance singularly fitted to display both […]”