dullness

The quality of being slow to understand.

Without sharpness or clearness of edge or point.

“the dullness of the pencil made his writing illegible”

A lack of visual brightness.

“the brightness of the orange sky was reflected in the dullness of the orange sea”

Lack of sensibility.

“there was a dullness in his heart”

“without him the dullness of her life crept into her work no matter how she tried to compartmentalize it.”

The quality of lacking interestingness.

“the stories were of a dullness to bring a buffalo to its knees”