烟蒂 A fag end is the last part of a cigarette, which people throw away when they have smoked the rest.
N-COUNT (尤指枯燥乏味或不重要的)结尾,末尾 If you refer to the fag end of something, you mean the last part of it, especially when you consider this part boring or unimportant.
He never had much confidence in his judgement at the fag-end of the working day. 到了快下班的百无聊赖的时候,他对自己的判断力从未有过信心。