Harassment is a form of discrimination that involves unwanted and unwelcome behavior, such as verbal or physical abuse, which is directed at an individual or group. Harassment can be based on any characteristic protected by law, including race, color, religion, sex, national origin, age, disability, or sexual orientation. The term 'harass endlessly' refers to the act of continuously subjecting someone to this type of behavior. In this context, the crossword solution 'TORMENT' is an appropriate word to describe the action of harassing someone endlessly.