[mass noun]deep sadness or gloom; melancholy 抑郁,忧郁 rain slithered down the windows, encouraging a creeping melancholia. 雨水顺窗流下,令人渐生郁闷。 ■(dated)a mental condition marked by persistent depression and ill-founded fears (旧)抑郁症
语源
late Middle English (denoting black bile): from late Latin (see melancholy)