/ ˈnætʃrəlnəs; NAmE / noun [ U ]
1.
the state or quality of being like real life :
The naturalness of the dialogue made the book so true to life.
2.
the quality of behaving in a normal, relaxed or innocent way :
Teenagers lose their childhood simplicity and naturalness.
3.
the style or quality of happening in a normal way that you would expect :
the naturalness of her reaction