melancholia

Etymology

From Late Latin melancholia, which was in turn borrowed from the Ancient Greek medical term μελαγχολία (melankholía, “blackness of the bile”), from μέλας (mélas), μελαν- (melan-, “black, dark, murky”) + χολή (kholḗ, “bile”).

noun

1. Deep sadness or gloom; melancholy
2. (pathology) depression, characterised by irrational fears, guilt and apathy