In Festus’ Epitoma operis de uerborum significatu Verrii Flacci, Greek appears in three different ways at least.
First, like Varro does it in his De lingua latina, Festus uses Greek to explain the etymology of a Latin word or to report the explanation of another author, as if Latin was descended from Greek; thus, the prepositional syntagm ex Graeco occurs more than thirty times in the treatise, for instance: Secus Valgius putat ex Graeco quod est ἑκάς dictum (Fest., 379, 1).
Second, locutions underlining the mention of a Greek word such as quod Graeci uocant, quod Graeci dicunt, quod a Graecis appellatur, quod graece dicitur, etc. are probably used to highlight the meaning of the Latin lemma. This way of referring to Greek words is not specific to Festus’ treatise: the same locutions occur in Cicero, Varro and other authors as well. However the question can be raised: Do these forms of reference have a particular function in the lexicographical practice of Festus or, before him, Verrius Flaccus? For example, a Greek word can be used to underline the polysemy of a Latin word: Molucrum non solum quo molae uerruntur dicitur, id quod Graeci μυλήκορον appellant, sed etiam tumor uentris, qui etiam uirginibus <incidere> solet (Fest., 124, 2).
Third, a loan word from Greek can also be the lemma itself (for instance: Nectar graece significat deorum potionem (Fest., 160, 18)) : Festus – or Verrius – obviously considers that the word belongs to the Latin lexical stock. Nevertheless he underlines that it is a Greek word by using the adverb graece (unlike the previous example: Festus seems not to be aware that molucrum is a loan from Greek μυλήκορον). These questions lead us to a broader research area: the use of loan words from Greek and their level of integration into Latin.