stalker
n. countablen. someone who follows or watches another person for a long time in a way that is scary or annoying. This person often makes the other person feel unsafe.
n. a person who obsessively and persistently follows, monitors, or harasses another individual, often causing psychological distress or fear. Frequently used in legal contexts to describe criminal behavior.
She called the police because she thought she had a stalker.
The celebrity had to hire extra security after a stalker tried to enter her private home twice in one week.
Modern technology has unfortunately made it easier for a stalker to track a victim's movements through social media posts and digital footprints.
Commonly used with the verb 'have' or 'be'. In legal contexts, it refers specifically to someone violating anti-stalking laws.