The two versions of the interpretation of the term “colloquial language” in the Russian Studies: the traditional one (the differences between the colloquial language and local dialects), the functional and stylistic interpretation (a fuzzy boundary between the conversational standard and colloquial language). Business colloquial language (univerbates, officialeses). Characteristics of colloquial univerbates: semantic extension, communicative demand. Traditional colloquial language characteristics. Taboo words.