anacoluthon

noun2

1. •
   A sentence or clause that is grammatically inconsistent, especially with respect to the type of clausal or phrasal complement for the initial clause.
2. •
   (rhetoric) Intentional use of such a structure.

   • Anacoluthon, though a grammatical defect, is a rhetorical beauty, if naturally produced or imitated; as, "If thou art he—but oh! how fallen!" — 1874