The term 'FEATURE OF A HORROR FILM' can be summarized by the crossword solution 'TERROR' (6 letters). TERROR is a common theme in horror films, as it is used to create suspense and fear in the audience. It is often used to evoke feelings of dread and anxiety, as well as to shock and surprise viewers. TERROR can be created through a variety of techniques, such as jump scares, dark lighting, and eerie music. It is also used to build tension and create a sense of unease.