Polyptoton /ˌpɒlᵻpˈtoʊtɒn/ is the stylistic scheme in which words derived from the same root are repeated (such as "strong" and "strength"). A related stylistic device is antanaclasis, in which the same word is repeated, but each time with a different sense. Another related term is figura etymologica.
In inflected languages polyptoton is the same word being repeated but appearing each time in a different case. (for example, "Iuppiter," "Iovis," "Iovi," "Iovem," "Iove" [in Latin being the nominative, genitive, dative, accusative, and ablative forms of "Iuppiter" (the god Jupiter), respectively]).
The form is relatively common in Latin Christian poetry and prose in a construction called the superlative genitive, in phrases such as sanctum sanctorum ("holy of holies"), and found its way into languages such as Old English, which naturally favored the alliteration that is part and parcel of polyptoton—in fact, polyptoton is "much more prevalent in Old English verse than in Latin verse." The specific superlative genitive in Old English, however, occurs only in Latinate Christian poems, not in secular poetry.
It is also used in public speaking, and several cases of use can be found in Churchill's speeches. Chesterton frequently resorted to this rhetorical device to create paradoxes:
[T]hough deserted by the un-English government of England, they asserted their own ancient character...
In combination with verbal active and passive voices, it points out the idea of a latent reciprocity:
Judge not, that ye be not judged
An alternative way to utilize the stylistic device is to develop polyptoton over the course of an entire novel, which is done in Mary Shelley's Frankenstein. Shelley combines polyptoton with periphrastic naming, which is the technique of referring to someone using several indirect names. The creature in Frankenstein is referred to by many names, such as "fiend", "devil", "being", and "ogre". However, the first name that Shelley uses in reference to the creature is "wretch". Throughout the novel, various forms of the term are used, such as "wretchedly" and "wretchedness", which is indicative of polyptoton. According to Duyfhuizen, the gradual development of polyptoton in Frankenstein is significant because it symbolizes the intricacies of one's own identity.