The term "poison pen" refers to a written attack or criticism meant to harm or discredit someone's reputation. Alternative phrases to describe this kind of behavior include "vitriolic letter," "venomous missive," and "malicious note." These terms highlight the insidious and harmful nature of using written language to inflict harm on others. Other synonyms may include "slanderous correspondence," "defamatory letter," and "hateful message." Regardless of the term used, the act of using the written word to attack and harm another person is unacceptable, and it is important to recognize and stand against this kind of behavior.