Sad

adj. sad·der, sad·dest
Affected or characterized by sorrow or unhappiness.
Expressive of sorrow or unhappiness.
Causing sorrow or gloom; depressing: a sad movie; sad news.
Deplorable; sorry: a sad state of affairs; a sad excuse.
Dark-hued; somber.

[Middle English, weary, sorrowful, from Old English sæd, sated, weary. See s- in Indo-European Roots.]

Synonyms: sad, melancholy, sorrowful, doleful, woebegone, desolate
These adjectives mean affected with or marked by unhappiness, as that caused by affliction.
Sad is the most general: “Better by far you should forget and smile/Than that you should remember and be sad” (Christina Rossetti).
Melancholy can refer to lingering or habitual somberness or sadness: a melancholy poet's gloomy introspection.
Sorrowful applies to emotional pain as that resulting from loss: sorrowful mourners at the funeral.
Woebegone suggests grief or wretchedness, especially as reflected in a person's appearance:
“His sorrow... made him look... haggard and... woebegone” (George du Maurier).
Desolate applies to one that is beyond consolation: “No one is so accursed by fate,/No one so utterly desolate,/But some heart, though unknown,/Responds unto his own” (Henry Wadsworth Longfellow).