Blue flu is a slang term that refers to a situation where a large number of police officers call in sick or do not report to work in protest or solidarity with a fellow police officer or department issue. Synonyms for "blue flu" include "police strike," "cops out," "police sick out," "blue strike," "police protest," and "law enforcement walkout." Essentially, these terms all describe a situation where police officers unite to make a statement by refusing to work for a period. Regardless of the terminology used, it is important to note that these actions often have significant impacts on public safety and the operational capacity of law enforcement agencies.