stalker

1. N-COUNT A stalker is someone who keeps following or contacting someone else, especially a famous person or a person they used to have a relationship with, in an annoying and frightening way. 騷擾者; 糾纏者

She had been followed and then trapped by a stalker. 她曾被一騷擾者跟蹤，然後中了他的圈套。