British slang is English-language slang originating from and used in the United Kingdom and also used to a limited extent in Anglophone countries such as Ireland, South Africa, Australia, Canada, and New Zealand, especially by British expatriates. It is also used in the United States to a limited extent. Slang is informal language sometimes peculiar to a particular social class or group and its use in Britain dates back to before the 15th century. The language of slang, in common with the English language, is changing all the time; new words and phrases are being added and some are used so frequently by so many, they almost become mainstream. While some slang words and phrases are used throughout Britain (e.g. knackered, meaning "exhausted"). Others are restricted to smaller regions, even to small geographical areas. The nations of the United Kingdom, which are England, Scotland, Wales and Northern Ireland, all have their own slang words, as does London. London slang has many varieties, the best known of which is rhyming slang. English-speaking nations of the former British Empire may also use this slang, but also incorporate their own slang words to reflect their different cultures. Not only is the slang used by British expats, but some of these terms are incorporated into other countries' everyday slang, such as in Australia, Canada and Ireland. British slang has been the subject of many books, including a seven volume dictionary published in 1889. Lexicographer Eric Partridge published several works about British slang, most notably Dictionary of Slang and Unconventional English, revised and edited by Paul Beale. Many of the words and phrases listed in this article are no longer in current use. Definitions of slang Slang is the use of informal words and expressions that are not considered standard in the speaker's dialect or language. Slang is often to be found in areas of the lexicon that refer to things considered taboo (see euphemism). It is often used to identify with one's peers and, although it may be common among young people, it is used by people of all ages and social groups. Collins English Dictionary (3rd edition) defines slang as "Vocabulary, idiom etc that is not appropriate to the standard form of a language or to formal contexts, may be restricted as to social status or distribution, and is characteristically more metaphorical and transitory than standard language". The Oxford Dictionary of English Grammar