The notion 'occasional word' or 'nonce word' has a very disputable character in linguistics. Language creativity is a peculiar feature of spoken communication and fiction works, which are a great source for enriching vocabulary of a certain language. The article is devoted to the problem of defining the notion of occasional words in Russian and Western linguistic schools, dealing with the typological peculiarities of author's or speaker's creativity in language. The research is a part of a great work on studying morphological, derivational, semantic, idiomatic, syntactic transformations, aiming to find a unified approach to the study of occasional words and phrases typical to almost all known languages
