dullness

Short definition from Wiktionary

Noun

1. 1
   The quality of being slow of understanding things; stupidity.
2. 2
   The quality of being uninteresting; boring; humorless or irksome.
3. 3
   Lack of interest or excitement.
4. 4
   The lack of visual brilliance; want of sheen.
5. 5
   bluntness.
6. 6
   The quality of not perceiving or kenning things distinctly.
7. 7
   Drowsiness.