The present article deals with the analysis of so-called intermediate categories or formations, which stand out of their structure. An intermediate category represents the emergence and essence of new unstable forms. The author studies polylexemes as a kind of intermediate category representations on the basis of language samples of the Russian mass-media texts and advertising slogans. The article reveals the differentiation of polylexemes and multifunctional words. Polylexeme is a language unit combining Cyrillic and Latin characters. Polylexeme represents a kind of the incorporation complex, and the incorporation can be of several types: Russian lexeme, on the one hand, and a morpheme, a quasi-morpheme, a symbol and lexemes of other languages, most regularly incorporated in Latin graphics. So, polylexemes constitute quite a new object of language studies due to their synthetic character revealed both in form and meaning. Qualification and description of polylexemes is proper within treating language as a semiotic system causing changes of functional relations of signs: language replaces one expressive form by another, tries new, not ordinary linguistic formations. According to expert opinion, the main external reasons for language and lexis changes are due to the two interrelated processes: globalization and integrated media space which lead to stylistic mismatch and linguistic expansion of the English-speaking world.