4 dull

dull
adj
(-er, -est)
1 not bright or clear 不鲜 明的; 不清楚的
    a dull colour, glow, thud 暗淡的颜色、 昏暗的光、 沉闷的响声
    dull (ie cloudy) weather 阴沉的天气

    dull of hearing, ie slightly deaf 听力不佳.
2 slow in understanding; stupid 迟钝的; 呆笨的
    a dull pupil, class, mind 迟钝的学生、 一班学生、 头脑.
3 lacking interest or excitement; boring; monotonous 枯燥无味的; 令人厌烦的; 单调的
    The conference was deadly dull. 会议开得死气沉沉的.
4 not sharp 不锋利的; 钝的: a dull knife 钝刀.
5 (of pain) not felt sharply (指疼痛)感觉不明显的, 隐约感觉到的: a dull ache 隐约的疼痛.
6 (of trade) not busy; slow (指生意)萧条的, 清淡的
    There´s always a dull period after the January sales. 在一月份大减价之後市面总要有一段清淡时期.
7 (idm 习语) (as) ,dull as `ditch-water (infml 口) very boring 极沉闷乏味的. dull, v [I, Tn]
(cause sth to) become dull (使某事物)变钝, 变迟钝
    Watching television dulls one´s wits. 看电视能使人头脑迟钝.
    She took drugs to dull the pain. 她吃了药以减轻疼痛.
    (fig 比喻) Time had dulled the edge of his grief. 岁月流逝冲淡了他的忧伤.