The boy is down in the dumps because of losing his favorite toy.
这孩子因为丢了最喜欢的玩具而闷闷不乐。
这个俚语最早源于中世纪英语。在英语中,“down”这个介词也可单独使用,形容人心情不好。“blue”和“low”也有这层意思。be down in the dumps常指“闷闷不乐”或“打不起精神”,也可引申为“垂头丧气,精神沮丧”。
Kevin:What is the most nagging thing in the world?
世界上最闹心的事是什么?
Rose:I am not quite sure about it. Why you ask such a question?
我不是很清楚,为什么这么问啊?
Kevin:I know it. It is that your girlfriend doesn't talk to you any more but you don't know why.
我知道,那就是你女朋友不理你但你又不知道为什么。
Rose:Oh, I see. I know why you are down in the dumps.
哦,我明白了,我说你怎么这么闷闷不乐呢。