Definitions:

1. a lack of visual brightness noun
   • the brightness of the orange sky was reflected in the dullness of the orange sea
2. lack of sensibility noun
   • There was a dullness in my heart.
3. the quality of lacking interestingness noun
   • the stories were of a dullness to bring a buffalo to its knees
4. without sharpness or clearness of edge or point noun
   • The dullness of the pencil made their writing illegible.

Synonyms:

• bluntness
• obtuseness