Melancholy is a quiet, settled sadness that does not point at anything in particular. Rain on a Sunday afternoon, an empty schoolyard in August, a song you loved when you were seventeen.
It is an adjective as well: a melancholy tune, a melancholy man watching the sea. Melancholy is not grief and not depression — nobody has died, you still eat and work, and part of you half enjoys the mood. The older sense is heavier: for centuries melancholy was a diagnosis, and the word melancholia is still used for a deep depressive state. Melancholic leans that way too, more clinical than melancholy itself. English keeps the word literary — you write melancholy more often than you say it, and in speech people reach for sad or down instead.
1nounmelancholyA quiet, lasting sadness with no single cause.
“A melancholy settled on the house once the last guest had gone.”
formal in this meaning — an editor’s judgement
synonyms: gloom, wistfulness, sorrow
2adjectivemournfulSad in a soft, thoughtful way; or causing that feeling.
“He plays melancholy songs on the piano when the weather turns.”
formal in this meaning — an editor’s judgement
3nounmedicineIn old medicine, black bile, and the depressive illness it was blamed for.
“Physicians of the time treated melancholy by bleeding the patient.”
melancholy is a mood.
You already know black. Melancholy is Greek for black liquid: the old doctors blamed a dark fluid in the body for a sadness that had no cause anyone could point to.
hooks ontoblack
Ancient medicine held that the body ran on four fluids, and one of them was black bile: μέλας, 'black', plus χολή, 'bile', giving Greek μελαγχολία. Too much of it and a person turned gloomy, so the name of the fluid became the name of the mood. It travelled through Old French melancolie into Middle English malencolie. The medicine was wrong; the word outlived it.
Ancient Greek
μελαγχολία — atrabiliousness
Old French
melancolie
Middle English
malencolie
English, today
melancholy
Built from
From Middle English malencolie, from Old French melancolie, from Ancient Greek μελαγχολία (“atrabiliousness”) (from μέλας, μελαν- (“black, dark, murky”) + χολή (“bile”)), referring to the humour which ancient Hippocratic and later Galenic medicine associated with sadness and despondency. Compare the Latin ātra bīlis (“black bile”). The adjectival use is a Middle English innovation, perhaps influenced by the suffixes -y, -ly. a doublet of melancholia.
Etymology from Wiktionary, CC BY-SA
Practised in Feelings & Character, Big Ideas, Moods & Relationships