POPO is a slang term used to refer to law enforcement officers, which is considered offensive in some situations. So, it is important to know some alternative terms that are more professional and respectful while referring to police officers. Some of the common synonyms for POPO are "police," "cops," "law enforcement," "officer," "sheriff," "patrol," "constable," and "trooper." These terms can be used without causing any offense and are widely recognized in the society. It is always better to choose the right words while communicating with law enforcement officials to avoid any misunderstandings and maintain a peaceful relationship with them.