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"
Fruit (slang) with the words essentially backwards; cool (look), delo (old) and nammow (woman). Out of the East End of London traditional Cockney rhyming slang developed, which works by taking two words that are related through a short phrase and using the first word to stand for a word that rhymes with the second. For instance, the most popular of these rhyming slang phrases used throughout Britain is probably "telling porkies" meaning "lies" as "pork pies" rhymes with lies. "Alright, me old fruit?" is an example of this as "fruit gum" is translated as meaning "chum" (a friend or acquaintance). "Cassell's Dictionary