The four-letter claim refers to the fact that a large number of (but not all) English swear words are incidentally four-character monosyllables. This description came into use during the first half of the twentieth century. Work Is a Four-Letter Word is the title of a 1968 British comedy film. 2  That Four-Letter Word is a 2006 independent film from India. 3  Welsh punk band Four Letter Word, formed in 1991, named themselves after the phrase.