lightsomeness

lightsomeness (http://definr.com/lightsomeness)

     n 1: the cheerful feeling you have when nothing is troubling you
          [syn: carefreeness, insouciance, lightheartedness]
     2: the gracefulness of a person or animal that is quick and
        nimble [syn: agility, legerity, lightness, nimbleness]
     3: the trait of being lighthearted and frivolous