1Lightness in movement or action; nimbleness, agility; (later also) flexibility of mind; mental agility.
2Generally. Lack of weight or weightiness; lightness of touch or feeling.
Mid 16th century (in an earlier sense). From Middle French legereté (French légèreté) thoughtlessness, thoughtless action, lack of seriousness, inconstancy, nimbleness, agility from leger + -eté.