This article deals with the specific features of English adaptation in new ethnic, social and cultural conditions. The purpose of the article is to identify the degree of lexical and semantic accommodation of English in the context of Anglo-Nigerian interaction on the example of idioms. The research material is Nigerian English online platform “Legit News”, whose media space provides readers and viewers with relevant information and entertainment content. It is established that news blocks in the form of written publications and video materials, TV shows, interactive videos form a media discourse, the specific features of which are the reflection of significant social aspects of Nigerian society in a short form, English nativisation process in the context of bilingualism and multiculturalism. It has been proved that English nativisation process is manifested by lexico-semantic variation. Based on a comparative analysis of British English and American English and Nigerian English idioms functioning in Nigerian English media discourse it has been proved that Nigerian English idioms can be identified as fully complying the norm, those partially corresponding to the norms and idioms which do not completely correspond to the norm in form and meaning. The method of quantitative analysis allowed determining that highly productive idioms include those partially not complying with the norm, while deviations relate to the inverted word order in idioms formation, morphological transformations, and the use of lexical synonyms. Idioms that are completely appropriate and inconsistent with the norm in form and meaning belong to unproductive ones in Nigerian English media discourse. Lexical and semantic changes in Nigerian English idioms functioning in Nigerian English media discourse are dictated by the influence of local languages and the need to follow the norms of native languages and cultures.