Nappy, curly, kinky hair that appears predominantly in women and men of African descent.
A combination of the words nappy or nap and natural. Nap-tural Glory.
There was an actual website that was named naptural glory, but for some reason the site can not be found currently. It was this site where I believe the term was first coined.
Apparently naptural can be spelled two ways.
Napptural or Naptural. Either way appears to be accepted by many.