O que é dull? O que é dull? Not intensely or keenly felt: a dull ache. Intellectually weak or obtuse; stupid.Lacking responsiveness or alertness; insensitive. Dispirited; depressed.Not brisk or rapid; sluggish: Business is dull. Not having a sharp edge or point; blunt: a dull knife. Arousing no interest or curiosity; boring: a dull play. Not bright or vivid. Used of a color: a dull brown. Cloudy or overcast: a dull sky. Not clear or resonant: a dull thud. To make or become dull.