what is melancholia

Melancholia (from Greek: µέλαινα χολή, melaina chole), also lugubriousness, from the Latin lugere, to mourn; moroseness, from the Latin morosus, self-willed, fastidious habit; wistfulness, from old English wist: intent, or saturnine, was a concept in ancient and pre-modern medicine. Melancholy was one of the four temperaments matching the four humours

In the 19th century, “melancholia” could be physical as well as mental, and melancholic conditions were classified as such by their common cause rather than by their properties

The name “melancholia” comes from the old medical belief of the four humours: disease or ailment being caused by an imbalance in one or other of the four basic bodily liquids, or humours. Personality types were similarly determined by the dominant humor in a particular person.