This article focuses primarily on the specific features of Nil Sorsky’s editing of the vocabulary of the Life of Theodore the Studite, which belongs to a distinct corpus of translations from Greek produced in medieval Rus’ by scribes of South Slavic origin. It describes newly identified cases in which semantic archaisms were replaced with equivalents regularly used in Old Russian written tradition (e.g. (домъ → храмъ, достоиныи → любьзныи, искоушенїе → искоусство, мьзда →приѡбрѣтенїе, пытати → испытовати, чинъ → санъ), as well as cases where vernacular Rus- sianisms were substituted with neutral Church Slavonic forms (e.g. потъсноутисѧ → попещисѧ). In addition, drawing on new evidence and the author’s previous research, the article provides a general characterisation of Nil’s system of lexical editing in the antigraphs of four vitae included in the Sobornik. It is established that the principal editorial techniques developed by the elder, under the infl uence of Athonite-Tarnovo traditions and the linguistic norms of original Old Russian hagiographic texts, include: the reduction of features of the local recension of Church Slavonic; the replacement of lexical and semantic archaisms with widely used equivalents in 15th-century literary Church Slavonic texts; the correction of translators’ and scribes’ errors on the basis of context; revisions reflecting the semantic evolution of lexemes; and, fi nally, the selection of synonyms regularly attested in Church Slavonic texts of the Old Russian recension of the late 15th – early 16th century.