<P> Loose lips sink ships is an American English idiom meaning "beware of unguarded talk". </P> <P> The phrase originated on propaganda posters during World War II . The phrase was created by the War Advertising Council and used on posters by the United States Office of War Information . </P> <P> The most famous poster that helped popularize the phrase (pictured at right) was created for the Seagram Distillers Corporation by the designer Seymour R. Goff (also known by the pseudonym "Ess - ar - gee" or Essargee). This type of poster was part of a general campaign of American propaganda during World War II to advise servicemen and other citizens to avoid spreading rumors--or truths--containing bad news that might hurt morale . Historian D'Ann Campbell argues that the purpose of the wartime posters, propaganda, and censorship of soldiers' letters was not to foil spies but, "to clamp as tight a lid as possible on rumors that might lead to discouragement, frustration, strikes, or anything that would cut back military production ." The British equivalent used "Careless Talk Costs Lives", and variations on the phrase "Keep mum", while in neutral Sweden the State Information Board promoted the wordplay "en svensk tiger" (the Swedish word "tiger" means both "tiger" and "keeping silent"), and Germany used "Schäm Dich, Schwätzer!" (English: "Shame on you, blabbermouth!"). </P>

Where does the phrase loose lips sink ships come from