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