dullness

the quality of being slow to understand

the quality of lacking interestingness; "the stories were of a dullness to bring a buffalo to its knees"

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."

without sharpness or clearness of edge or point; "the dullness of the pencil made his writing illegible"