Обратна топонимична деривация в руския и в българския език

The article studies groups of geographic names and detoponymic adjectives in contemporary Russian and in contemporary Bulgarian which from the synchronic point of view are reverse derivatives, i. e. derived words which function as formative for words of which they derive. Among toponyms in both languages there are full (formal-semantic) and formal (only at the level of expression) reverse derivatives. Adjectives are only formal reverse derivatives. Reverse derivation in toponyms functions within the framework of double derivation, along with the lexico-semantic one. The lexical groups in Russian and Bulgarian in question are characterized by a high degree of parallelism.