Read the dictionary definition of dull. All definitions for this word.
1. make less lively or vigorous
1. Middle age dulled her appetite for travel
2. become dull or lusterless in appearance; lose shine or brightness
1. the varnished table top dulled with time
3. become less interesting or attractive
4. make dull in appearance
1. Age had dulled the surface
5. make dull or blunt
1. Too much cutting dulls the knife's edge
6. make numb or insensitive
1. The shock numbed her senses
7. deaden (a sound or noise), especially by wrapping
8. (of business) not active or brisk
1. business is dull (or slow)
2. a sluggish market
9. emitting or reflecting very little light
1. a dull glow
2. dull silver badly in need of a polish
3. a dull sky
10. (of color) very low in saturation; highly diluted
1. dull greens and blues
11. slow to learn or understand; lacking intellectual acuity
1. so dense he never understands anything I say to him
2. never met anyone quite so dim
3. although dull at classical learning, at mathematics he was uncommonly quick
4. dumb officials make some really dumb decisions
5. he was either normally stupid or being deliberately obtuse
6. worked with the slow students
12. darkened with overcast
1. a dark day
2. a dull sky
3. the sky was leaden and thick
13. not having a sharp edge or point
1. the knife was too dull to be of any use
14. not keenly felt
1. a dull throbbing
2. dull pain
15. lacking in liveliness or animation
1. he was so dull at parties
2. a dull political campaign
3. a large dull impassive man
4. dull days with nothing to do
5. how dull and dreary the world is
6. fell back into one of her dull moods
16. so lacking in interest as to cause mental weariness
1. a boring evening with uninteresting people
2. the deadening effect of some routine tasks
3. a dull play
4. his competent but dull performance
5. a ho-hum speaker who couldn't capture their attention
6. what an irksome task the writing of long letters is
7. tedious days on the train
8. the tiresome chirping of a cricket
9. other people's dreams are dreadfully wearisome
17. being or made softer or less loud or clear
1. the dull boom of distant breaking waves
2. muffled drums
3. the muffled noises of the street
4. muted trumpets
18. not clear and resonant; sounding as if striking with or against something relatively soft
1. the dull thud
2. thudding bullets
19. blunted in responsiveness or sensibility
1. a dull gaze
2. so exhausted she was dull to what went on about her