noun
A loanword for a pensive, subdued sadness, often with a literary or psychological tone. Used similarly to English 'melancholy'.
秋の夕暮れには、なんとなくメランコリーな気分になる。
On autumn evenings, I somehow feel a sense of melancholy.
憂鬱 is a more common and heavier native word for depression or gloom, while メランコリー is a softer, more literary loanword.
Borrowed from English 'melancholy', ultimately from Greek 'melankholia'.