1. in a way that lacks brightness, sharpness, or intensity
2. in a boring or uninteresting manner
3. in a way that shows little intelligence or awareness

Examples

• The old lamp glowed dully in the corner of the room.
• He stared dully at the television screen.
• The metal surface reflected the light dully.
• She spoke dully about her weekend plans.
• The student answered the question dully, showing no enthusiasm.
• The knife blade had been worn dully from years of use.
• He dully repeated the same mistake over and over.