flatness >> ˈflatnəs
Definition: [noun] the quality of having a level surface without raised areas or indentations.
Example: the flatness of the external surface
Definition: [noun] lack of emotion or enthusiasm; dullness.
Example: neither the editing nor the score do much to help the film's emotional flatness
Definition: [noun] loss of effervescence in a sparkling drink.
Definition: [noun] the quality of a musical sound being below normal pitch.
Example: the flatness of the vocals