Costermonger a secret language, a code which only other costermongers understood. In her book, "Shadows of the Workhouse", Jennifer Worth observed that "Costers... spoke to each other almost entirely in back slang; incomprensible to an outsider." Many costermongers also used "rhyming slang"; where any word can be substituted with another word that rhymes with it. Examples of rhyming slang include: "tin lids" or "dustpan lids" for "kids"; "jimmy grant" for "emigrant"; "apple and pears" for "stairs"; "rubbidy dub" for "pub" and "trouble and strife" for "wife". The selection of rhyming words often suggested a symbolic association. For example, a "sorrowful tale"
Rhyming slang or by criminals to confuse the police (see thieves' cant). The English academic, lexicographer and radio personality Terence Dolan has suggested that rhyming slang may have been invented by Irish immigrants to London "so the actual English wouldn't understand what they were talking about." Many examples of rhyming slang are based on locations in London, such as "Peckham Rye", meaning "tie" (as in necktie), which dates from the late 19th century; "Hampstead Heath", meaning "teeth" (usually as "Hampsteads"), which was first recorded in 1887; and "Barnet Fair", meaning "hair", which dates from the 1850s. By the mid-20th century many rhyming