Abstract: (The Canon of Lexical Borrowing – Greek Words into Latin) The question we take as a starting point concerns the notion of “canon” in the process of lexical borrowing: does the grammatical norm impose the strict preservation of the phono-morphological features of the word from the source language or rather requires the adaptation of the borrowed word to the phonetic and morphological system of the target language? We shall analyze from this point of view the Greek words that were borrowed in classical Latin, taking into account, on the one hand, the diastratic variation and, on the other hand, the various attempts of the speakers to maintain a balance between the orthography and pronunciation in the source language and the phono-morphological specificity of Latin. Thus, we will trace back the phonetic and morphological variations that a Greek word may suffer in its process of integration into Latin, as reflected in the ancient authors and especially in the classical and late grammarians that offered various explanations of the words in question. In what form did these Greek words settle in spoken Latin? Or, better said, did they really settle in one form? Or did diatopic, diachronic and diastatic variants circulate? To answer these questions, we will use the testimony of the Romance languages: there are situations where, for a single Greek term, there must be reconstructed several variants, either synchronous - belonging to the various diatopic varieties of the spoken language – or diachronic ones.