dull

Darkened with overcast.

“a dull sky”

(of business) not active or brisk.

“business is dull (or slow)”

Blunted in responsiveness or sensibility.

“a dull gaze”

“so exhausted she was dull to what went on about her”

Emitting or reflecting very little light.

“a dull glow”

“dull silver badly in need of a polish”

Lacking in liveliness or animation.

“he was so dull at parties”

“a dull political campaign”

Not having a sharp edge or point.

“the knife was too dull to be of any use”

Not keenly felt.

“a dull throbbing”

“dull pain”

(of color) very low in saturation; highly diluted.

“dull greens and blues”

So lacking in interest as to cause mental weariness.

“a dull play”

“his competent but dull performance”

Slow to learn or understand; lacking intellectual acuity.

“although dull at classical learning, at mathematics he was uncommonly quick”

Being or made softer or less loud or clear.

“the dull boom of distant breaking waves”

Not clear and resonant; sounding as if striking with or against something relatively soft.

“the dull thud”

Become dull or lusterless in appearance; lose shine or brightness.

“the varnished table top dulled with time”

Make dull in appearance.

“Age had dulled the surface”

Make less lively or vigorous.

“Middle age dulled her appetite for travel”

Make numb or insensitive.

Become less interesting or attractive.

Deaden (a sound or noise), especially by wrapping.

Make dull or blunt.

“Too much cutting dulls the knife's edge”