lack of interest or excitement

tasks of such repetitive and numbing dullness

a desert of unremitting flatness and dullness

the dullness of domestic life

lack of brightness, vividness, or sheen

flowery options to brighten up the dullness of autumn

the summer light cut into the dullness of the room

the dullness of the colours

the quality of being slow to understand; stupidity

critical comments on the stupidity or dullness of those in authority

dullness of comprehension