A code word is a word or a phrase designed to convey a predetermined meaning to an audience who know the phrase, while remaining inconspicuous to the uninitiated. For example, a public address system may be used to make an announcement asking for "Inspector Sands" to attend a particular area, which staff will recognise as a code word for a fire or bomb threat, and the general public will ignore.

Medical use

Military and espionage use

Code names are used for military and espionage purposes as labels for people, locations, objects, projects and plans the details of which are intended to remain secret to the uninitiated. For example, the code name of "Mogul" is used by the United States Secret Service to refer to the former President of the United States Donald Trump. The United States Navy mistook the code word "Friend of Dorothy," meaning an LGBT individual, as meaning literally a person who was a friend of someone by the name of "Dorothy," and investigated on that basis.

Other usages

Informal code words and propaganda

An informal code word is a term used without formal or prior agreement to communicate to a subset of listeners or readers predisposed to see its double meaning. Informal code words can find use in propaganda, distinct from use of euphemistic code words to delay or avoid emotional responses in the audience. They may be intended to be construed as generalized platitudes by the majority of listeners, but as quite specific promises by those for whom the specific wording was crafted.