The article analyses the translation correlates of ἀρετη, πολιτεία and φιλοσοφία in Constantine of Preslav’s Didactic Gospel. Their contextual meanings are systemised together with their Old Bulgarian transponents. Other Greek words that are translated by the same slavic transponents are analysed and the data are compared to the information in the major palaeoslavic dictionaries. The observations reveal that φιλοσοφία and ἀρετη are rendered by a wide range of lexemes whose array rivals that in far more voluminous Old Bulgarian corpora. It can be shown that the choice of synonyms for the three polysemous Greek nouns is not arbitrary but consistent with the meaning in a specific context. It appears that there is a tendency towards rendering each meaning of a Greek word by one particular Slavic word, i.e. a tendency to transform semantic differentiation in the source language into lexical differentiation in the target language. There is also a rather clearly noticeable semantic differentiation between the synonymous lexemes житиѥ and жиꙁнь and it is motivated not by the translated Greek words but by their contextual meanings, in which житиѥ refers more often to the earthly life whereas жиꙁнь means the eternal life.