Auszug aus dem englischssprachigen Wikipedia Artikel: http://en.wikipedia.org/wiki/Weird_fiction
Weird fiction is speculative literature written in the late 19th and early 20th century. Popular writers of weird tales included H. P. Lovecraft, Lord Dunsany, Arthur Machen, and M. R. James. Weird fiction is distinguished from horror and fantasy in that it predates the niche marketing of genre fiction. Because generic conventions had not been established, weird tales often blend the supernatural, mythical, and even scientific. British writers, for example, published their work in mainstream literary magazines even after American pulp magazines became popular. Although chiefly a historical description, weird fiction has also been used to refer to contemporary slipstream fiction that blends horror, fantasy, and science fiction.
The true weird tale has something more than secret murder, bloody bones, or a sheeted form clanking chains according to rule. A certain atmosphere of breathless and unexplainable dread of outer, unknown forces must be present; and there must be a hint, expressed with a seriousness and portentousness becoming its subject, of that most terrible conception of the human brain–a malign and particular suspension or defeat of those fixed laws of Nature which are our only safeguard against the assaults of chaos and the daemons of unplumbed space.
Although Lovecraft was one of the few early 20th-century writers to describe their work as weird fiction, the term has enjoyed a contemporary revival in New Weird fiction. China Miéville often uses “weird fiction” as a way to describe his quasi science fiction and unconventional fantasy. Many horror writers have situated themselves within the tradition of weird fiction, including Clive Barker, who describes his fiction as fantastique, and Ramsey Campbell, whose work is deeply influenced by Lovecraft.