"Sentimental pessimism or melancholy over the state of the world"
Weltschmerz (from the German meaning world-pain or world-weariness) is a term coined by the German author Jean Paul and denotes the kind of feeling experienced by someone who understands that the physical reality can never satisfy the demands of the mind. It is also used to denote the feeling of sadness when thinking about the evils of the world.
The modern meaning of Weltschmerz in the German language is the psychological pain caused by sadness, that can occur when realizing that someone's own weaknesses are caused by the inappropriateness and cruelty of the world and (physical and social) circumstances.
"Gleaned" from www.yourdictionary.com and Wikipedia; image from the Canadian comic strip, Weltschmerz.