not sharp; blunt

a dull knife.

causing boredom; tedious; uninteresting

a dull sermon.

not lively or spirited; listless.

not bright, intense, or clear; dim

a dull day; a dull sound.

having very little depth of color; lacking in richness or intensity of color.

slow in motion or action; not brisk; sluggish

a dull day in the stock market.

mentally slow; lacking brightness of mind; somewhat stupid; obtuse.

lacking keenness of perception in the senses or feelings; insensible; unfeeling.

not intense or acute

a dull pain.

to make or become dull.

adverb

densely , obtusely , slowly , lethargically , sluggishly , listlessly , dimly