[dull] adj [ME dul; akin to OE dol foolish, OIr dall blind] (13c) 1: mentally slow: stupid
2. a: slow in perception or sensibility: insensible b: lacking zest or vivacity: listless
3: slow in action: sluggish
4. a: lacking in force, intensity, or sharpness b: not resonant or ringing "a ~ booming sound"
5: lacking sharpness of edge or point
6: lacking brilliance or luster
7. of a color: low in saturation and low in lightness 8: cloudy 9: tedious, uninteresting -- dull.ness or dul.ness n -- dul.ly adv syn dull, blunt, obtuse mean not sharp, keen, or acute. dull suggests a lack or loss of keenness, zest, or pungency "a dull pain" "a dull mind". blunt suggests an inherent lack of sharpness or quickness of feeling or perception "a person of blunt sensibility". obtuse implies such bluntness as makes one insensitive in perception or imagination "too obtuse to realize the remark was offensive". syn see in addition stupid
[2]dull vt (13c): to make dull ~ vi: to become dull