Noun:
a feeling of thoughtful sadnessa constitutional tendency to be gloomy and depresseda humor that was once believed to be secreted by the kidneys or spleen and to cause sadness and melancholy
Adjective:
characterized by or causing or expressing sadness;growing more melancholy every hour
her melancholic smile
we acquainted him with the melancholy truth
grave or even gloomy in character;solemn and mournful music
a suit of somber black
a somber mood
sad，unhappy，gloomy，blue，sorrowful，melancholy这些形容词均含“忧伤的，悲哀的，伤感的”之意。
sad最常用词，泛指一切形式的悲伤，着重暂时的不幸或感觉的忧伤。
unhappy多指日常生活中遇到不如意的事而感到不愉快、不幸，侧重指心理状态。
gloomy指愁眉苦脸，令他人也感到扫兴。
blue非正式用词，语气较随便，指较强烈的忧郁或沮丧。
sorrowful多指因丧失亲人等原因所引起的悲哀，也指由于错误而产生的悔恨交加的心情。
melancholy指经常性的忧郁或悲哀，多用于文学描写中。
近义词 low低的down向下funk恐惧sad悲哀的grief悲痛black黑的gloom黑暗blue蓝色的sorrow悲伤sadness悲哀gloomy阴暗的dismal阴沉的somber微暗的sombre昏暗的pensive沉思的wistful渴望的forlorn孤独的sorry对不起的painful痛苦的elegiac挽歌的doleful悲哀的dejection沮丧depression沮丧mournful悲恸的wretched可怜的downcast气馁的glum闷闷不乐的gloominess黑暗unhappy不快乐的miserable痛苦的sorrowful悲伤的woebegone忧愁的depressed沮丧的cheerless沉闷的unhappiness忧愁downhearted消沉的melancholic忧郁的funereal适合葬礼的despondency失去勇气depressing令人沮丧的despairing感到绝望的black bile黑胆汁体液down in the dumps气馁反义词 merry愉快的happy高兴的cheerful高兴的pleasant令人愉快的delightful令人愉快的gay同性恋多指男同性恋）…
用作名词(n.A mood of melancholy descended on us.一种悲伤的情绪袭上我们的心头。用作形容词adj.
用作表语
S+be+～He pined and became melancholy.他衰弱憔悴，心情忧郁。
名词54%,形容词46%
Her sweet words dispersed his melancholy.她的温柔话语驱散了他的忧愁。用作形容词You must rid yourself of this melancholy mood.你一定要摆脱这种忧愁情绪。