found: Moving image genre-form guide online, Sept. 14, 2007(horror: Fictional work portraying the dark side of life, the unknown, the forbidden, and the supernatural, with the primary aim of frightening the viewer in an entertaining, cathartic manner)
found: López, D. Films by genre, ©1993(Horror Film (Gorefest, Monster Movie, Terror Film); the genre is very diversified, having multiple subgenres; horror movies are better classified thematically, by content, or by the nature of the monster appearing in them; horror mixes well with science fiction and sometimes it is difficult to decide to which genre a film belongs; at times, a horror movie is referred to as a "chiller," a "chiller-diller," or a "spinechiller," terms which are also used to describe a thriller. "Shocker" is applied to that which causes a sensational effect, that is, to what is horrifying, offensive, or repulsive. As such it applies to a horror film as well as to a sex film. See also Gore Film, Haunted House Film, Kaiju Eiga, Psychopathic Thriller, Sex and Violence Film, Vampire Film, Witch Film, Zombie Movie)
found: Britannica online, Feb. 9, 2017(Horror film, motion picture calculated to cause intense repugnance, fear, or dread. Horror films may incorporate incidents of physical violence and psychological terror; they may be studies of deformed, disturbed, psychotic, or evil characters; stories of terrifying monsters or malevolent animals; or mystery thrillers that use atmosphere to build suspense. The genre often overlaps science-fiction films and film noir)
found: Cambridge dictionary online, Feb. 9, 2017(horror film: a film in which very frightening or unnatural things happen, for example dead people coming to life and people being murdered)
found: Collins English dictionary online, Feb. 9, 2017(horror film: a film with a frightening storyline and atmosphere)
found: Longman dictionary of contemporary English online, Feb. 9, 2017(horror movie especially American English, horror film British English: a film in which strange and frightening things happen)
found: Macmillan dictionary online, Feb. 9, 2017(horror film: a film that is intended to frighten people, especially one about murders, frightening creatures, or evil people)