Melancholy

mel·an·chol·y

[mel-uhn-kol-ee]  plural mel·an·chol·ies

noun

1.  a gloomy state of mind, especially when habitual or prolonged; depression.

2.  sober thoughtfulness; pensiveness.

3.  Archaic. 
     a.  the condition of having too much black bile, considered in ancient and medieval medicine to cause gloominess and depression.

     b.  black bile.

adjective

4.  affected with, characterized by, or showing melancholy; mournful; depressed: a melancholy mood.

5.  causing melancholy or sadness; saddening: a melancholy occasion.

6.  soberly thoughtful; pensive.

[From http://dictionary.reference.com/browse/melancholy?s=t ]