Over the last decades, especially in the Slavic countries, onomastic disciplines and their terminologies have significantly improved. Therefore, in ethnonymics – a study of the names of peoples and, in a broader sense, the names of the inhabitants of physiographic and/or administrative regions – not only necessary terms, but also terms whose purposefulness is at best debatable, have been introduced. This paper examines whether such terms include the Bulgarian term govoren etnonim and the Anglophone term shibbolethnonym, which denote ethnonyms motivated by some speech characteristic of the community in question. The analysis is performed from the standpoint of Serbian onomastics and etymology using appropriate examples from different varieties of the Serbian language: the standard, rural vernacular, and informal varieties of urban environments (i.e. colloquial style and youth jargon or slang). Examples are classified into shibbolethnonyms ʻproperʼ, with more or less clear motivation reflected in the imitation of phonological, grammatical and/or lexical features in the speech of another ethnic or regional community (Švabenzi infrm. ‘Germans’), and ʻfalseʼ shibbolethnonyms, with blurred motivation or meaning which only describe the speech characteristics of the Other (Nijemci stnd. ‘Germans’). We particularly point to the examples which, in addition to speech characteristics, (re)produce positive stereotypes about the greatest closely related nation (baćuška ‘a Russian man’) and regional communities of the same, Serbian or Croatian people (đetić ‘a man from Montenegro’; prika ‘a man from Slavonia’, rođo ‘a man from Herzegovina’). Finally, based on the number and importance of the presented examples, it is concluded that the introduction of the notion in question is necessary, even if one takes the view that yet another onomastic term, in addition to many already accepted, may appear undesirable.