tedium: is likely to suggest dullness and lowness of spirits resulting from irksome inactivity or sameness or monotony of occupation: could scarcely bear the ~ of listening to one long lecture after another.         如it was another day of mind-numbing tedium又是一个令人麻木的单调乏味的日子，如to relieve tedium of everyday life/job缓解乏味的生活/枯燥的工作
irksome使人厌烦失去耐心


boredom: adds suggestions of listlessness, dreariness, and unrest that accompany an environment or situation or company that fails to stimulate or challenge: seeks distraction from the ~ of housework.        （无聊有2个意思，1、精神空虚，如闲得/觉得无聊 2、没有作用没有意义因而令人生厌，如无聊的人/事/话，这里用1。正文中listless无精打采dreary沉闷乏味unrest坐立不安都是无聊的表现，没有分别译出）       如broadly speaking, human beings may be divided into three classes: those who are toiled to death, those who are worried to death, and those who are bored to death大体来说人分三类: 劳累死的、担忧死的、和无聊死的，选自新四第58篇丘吉尔的《绘画消遣painting as a passtime》  


ennui: stresses profound dissatisfaction or weariness of spirit and often suggests physical depression as well as boredom: a life of self-indulgence that later left him subject to feelings of ~.         depression抑郁是最严重的情绪低落，一般需要治疗，没有译出  


doldrums: applies to a period of depression marked by listlessness, lagging spirits, and despondency: failed to raise her from the ~; or implies a dull inactive state: the stock market has been in the ~ lately.      despondency绝望最严重的失望，因为已经无可挽回，如因丧失亲人despondent over the death of her father父亲的去世使她感到绝望


tedium单调枯燥: 表示工作生活单调使人感到沉闷枯燥，boredom无趣无聊:  表示人或事物无趣(fails to stimulate刺激challenge挑战)使人感到沉闷无聊，ennui厌倦无聊: 比较正式，强调无聊的程度深，doldrums消沉萧条: 用于人表示抑郁消沉绝望，用于事物表示萧条


记忆方法: 1）首字母TBED债<==厌倦

         2）练习一下

         3）厌倦的意思是厌烦倦怠mean a state of dissatisfaction and weariness.