melancholy

Etymology

From Middle English malencolie, from Old French melancolie, from Ancient Greek μελαγχολία (melankholía, “atrabiliousness”), from μέλας (mélas), μελαν- (melan-, “black, dark, murky”) + χολή (kholḗ, “bile”). Compare the Latin ātra bīlis (“black bile”). The adjectival use is a Middle English innovation, perhaps influenced by the suffixes -y, -ly.

noun

1. (historical) Black bile, formerly thought to be one of the four "cardinal humours" of animal bodies.
   Melancholy, cold and dry, thick, black, and sour, […] is a bridle to the other two hot humours, blood and choler, preserving them in the blood, and nourishing the bones. , Bk.I, New York 2001, p.148
2. Great sadness or depression, especially of a thoughtful or introspective nature.
   As to Ernest... He is quite as nervously broken down as I am but it manifests itself in different ways. His inclination is towards megalomania and mine towards melancholy. 1936 Sept. 15, F. Scott Fitzgerald, letter to Beatrice Dance

adj

1. (literary) Affected with great sadness or depression.
   Melancholy people don't talk much.
   “[…] the awfully hearty sort of Christmas cards that people do send to other people that they don't know at all well. You know. The kind that have mottoes[…]. And then, when you see [the senders], you probably find that they are the most melancholy old folk with malignant diseases. […]” 1922, Ben Travers, chapter 1, in A Cuckoo in the Nest
   And then the band slowed the tempo / And the music gets you down / Ah-ah-ah, ah-ah-ah-ah, ah / It was the same old song / With a melancholy sound / Ah-ah-ah, ah-ah-ah-ah, ah 1981, Greg Kihn, Steve Wright, “The Breakup Song (They Don't Write 'Em)”, in RocKihnRoll, performed by The Greg Kihn Band