The article explores the semantic evolution of the adverb stoicheski (English stoically) and its synonyms. It examines the potential of these lexemes to express both abstract (philosophical) and concrete ideas related to Russia’s cultural-historical and spiritual-intellectual traditions. The article aims to determine the nature of the semantic relations between the adverb stoicheski and the lexemes stoiko (English steadfastly), ustoichivo (English firmly, steadily), and ustoino (English firmly, steadily). The inner form of the key lexeme in this work is associated with the name of Stoics, which makes the analysis of this lexical unit important for understanding the influence of Stoicism on the Russian language as well as Russian thought and culture. The relevance of this research is determined by the necessity to trace the historical dynamics of lexical semantic processes in adverbial vocabulary (such as metaphorisation, broadening and nar-rowing of meanings, lexicalisation) that have occurred over several centuries. The study employed comparative-con-trastive, etymological, descriptive (in conjunction with generalisation and classification techniques) methods as well as componential and contextual analysis. Thorough examination of the above-mentioned adverbs suggests that the adverb stoicheski entered the Russian language in the 18th century under the influence of the growing interest in Stoicism and the Stoics in Russia. Their ideas permeated various spheres of Russian people’s cultural and intellectual life thanks to translated philosophical works. The conducted research shows that the similarity between the meanings of the adverbs stoicheski (English stoically) and stoiko (English steadfastly) is not accidental. It is determined by a combination of circumstances. On the one hand, the similarity may be associated with the evolution of the internal semantic motivation in these lexemes. Such motivation is based both on the phonetic similarity of their roots and on the presence of a deep etymological connection due to the ancient stem commonality which the speakers perceived intuitively. On the other hand, one can assume a phonetic convergence (sound similarity) of the lexemes and a possible semantic calque from the French language.