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 spread beyond the purely dialectal and some examples are to be found in the mainstream British English lexicon, although many users may be unaware of the origin of those words. Most of the words changed by this process are nouns, but a few are adjectival e.g. "bales" of cotton (rotten), or the adjectival phrase "on one's tod" for "on one's own", after Tod Sloan, a famous jockey. Rhyming slang is believed to have originated in the mid-19th century in the East End of London, with several sources suggesting some time in the 1840s. According to a Routledge's slang dictionary from