dullness

Concise Oxford English Dictionary © 2008 Oxford University Press:
dull/dʌl/

▶adjective

• 1 lacking interest or excitement.

• 2 not bright or shiny.

  ■ (of the weather) overcast.

• 3 slow to understand.

  ■ slow-moving.

• 4 indistinctly felt or heard.

▶verb make or become dull.

– derivatives
dullish adjective,
dullness (also dulness) noun,
dully /ˈdʌlˌli/ adverb.

– origin OE dol ‘stupid’, of Gmc origin.