melancholy

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Sadness or depression of the spirits; gloom: "There is melancholy in the wind and sorrow in the grass” ( Charles Kuralt).
2. n. Pensive reflection or contemplation.
3. n. Archaic Black bile.
4. n. Archaic An emotional state characterized by sullenness and outbreaks of violent anger, believed to arise from black bile.
5. adj. Affected with or marked by depression of the spirits; sad. See Synonyms at sad.
6. adj. Tending to promote sadness or gloom: a letter with some melancholy news.
7. adj. Pensive; thoughtful.

Century Dictionary and Cyclopedia

1. n. Same as melancholia; in old use, insanity of any kind.
2. n. A gloomy state of mind, particularly when habitual or of considerable duration; depression of spirits arising from grief or natural disposition; dejection; sadness. Also, in technical use, melancholia.
3. n. Sober thoughtfulness; pensiveness.
4. n. Bitterness of feeling; ill nature.
5. n. Synonyms Hypochondria, gloominess, despondency.
6. Produced by melancholia or madness of any kind.
7. Affected by depression of spirits; depressed in spirits; dejected; gloomy.
8. Given to contemplation; thoughtful; pensive. See I., 3.
9. Producing or fitted to produce sadness or gloom; sad; mournful: as, a melancholy fact; a melancholy event.
10. Grave or gloomy in character; suggestive of melancholy; somber.

Wiktionary

1. adj. Affected with great sadness or depression.
2. n. Black bile, formerly thought to be one of the four "cardinal humours" of animal bodies.
3. n. Great sadness or depression, especially of a thoughtful or introspective nature.

GNU Webster's 1913

1. n. Depression of spirits; a gloomy state continuing a considerable time; deep dejection; gloominess.
2. n. Great and continued depression of spirits, amounting to mental unsoundness; melancholia.
3. n. Pensive maditation; serious thoughtfulness.
4. n. Ill nature.
5. adj. Depressed in spirits; dejected; gloomy dismal.
6. adj. Producing great evil and grief; causing dejection; calamitous; afflictive.
7. adj. Somewhat deranged in mind; having the jugment impaired.
8. adj. Favorable to meditation; somber.

WordNet 3.0

1. n. a feeling of thoughtful sadness
2. n. a humor that was once believed to be secreted by the kidneys or spleen and to cause sadness and melancholy
3. adj. grave or even gloomy in character
4. n. a constitutional tendency to be gloomy and depressed
5. adj. characterized by or causing or expressing sadness