Extended metaphor

An extended metaphor, also known as a conceit or sustained metaphor, is when an author exploits a single metaphor or analogy at length through multiple linked vehicles, tenors, and grounds throughout a poem or story. Tenor is the subject of the metaphor, vehicle is the image or subject that carries the weight of the comparison, and ground is the shared proprieties of the two compared subjects. Another way to think of extended metaphors is in terms of implications of a base metaphor. These implications are repeatedly emphasized, discovered, rediscovered, and progressed in new ways.