What is the meaning of lightness?

noun

• A feeling of joy and pride.
  • synonyms: elation, high spirits
• The property of being comparatively small in weight.
  • usage: "the lightness of balsa wood"
  • synonyms: weightlessness
• The gracefulness of a person or animal that is quick and nimble.
  • synonyms: agility, legerity, lightsomeness, nimbleness
• Having a light color.
• The visual effect of illumination on objects or scenes as created in pictures.
  • usage: "he could paint the lightest light and the darkest dark"
  • synonyms: light
• The trait of being lighthearted and frivolous.
  • synonyms: lightsomeness