| verb | make dull in appearance “Age had dulled the surface” |
| verb | become dull or lusterless in appearance; lose shine or brightness “the varnished table top dulled with time” |
| verb | deaden (a sound or noise), especially by wrapping |
| verb | make numb or insensitive “The shock numbed her senses” |
| verb | make dull or blunt “Too much cutting dulls the knife's edge” |
| verb | become less interesting or attractive |
| verb | make less lively or vigorous “Middle age dulled her appetite for travel” |
| adjective | having lost or been caused to lose interest because of overexposure “the mind of the audience is becoming dulled” |
| adjective | made dull or blunt |
| adjective | deprived of color “colors dulled by too much sun” |
| muffler | noun | a device that decreases the amplitude of electronic, mechanical, acoustical, or aerodynamic oscillations |
| mute | noun | a device used to soften the tone of a musical instrument |
| damper | noun | a device that decreases the amplitude of electronic, mechanical, acoustical, or aerodynamic oscillations |
| dullard | noun | a person who evokes boredom |