A characteristic of Homer's style is the use of epithets, as in "rosy-fingered" Dawn or "swift-footed" Achilles. Epithets are used because of the constraints of the dactylic hexameter (i.e., it is convenient to have a stockpile of metrically fitting phrases to add to a name) and because of the oral transmission of the poems; they are mnemonic aids to the singer and the audience alike.
Formulae in epic poetry from various Indo-European traditions may be traced to a common tradition. For example, the phrase for "everlasting glory" or "undying fame" can be found in the Homeric Greek as ? / kléos áphthiton and Vedic Sanskrit as / ?rávo ák?itam. These two phrases were, in terms of historical linguistics, equivalent in phonology, accentuation, and quantity (syllable length). In other words, they descend from a fragment of poetic diction (reconstructable as Proto-Indo-European *?léwos d?gitom) which was handed down in parallel over many centuries, in continually diverging forms, by generations of singers whose ultimate ancestors shared an archetypal repertoire of poetic formulae and narrative themes.
Epithets alter the meaning of each noun to which they are attached. They specify the existential nature of a noun; that is to say, Achilles is not called "swift-footed" only when he runs; it is a marker of a quality that does not change. Special epithets, such as patronymics, are used exclusively for particular subjects and distinguish them from others, while generic epithets are used of many subjects and speak less to their individual characters. In these examples, the epithet can be contradictory to the past state of the subject: in Odyssey VI.74, for instance, Nausicaa takes her "radiant clothing", ?, to be washed; since it is dirty, it is unlikely to be radiant.