Light"-hearted*ness

from The Collaborative International Dictionary of English v.0.48

Light-hearted \Light"-heart`ed\ (l[imac]t"h[aum]rt`[e^]d), a.
   Free from grief or anxiety; gay; cheerful; merry. --
   {Light"-heart`ed*ly}, adv. -- {Light"-heart`ed*ness}, n.
   [1913 Webster]