Allegory
A concrete, developed representation of an abstract idea, often embodied by a character or an entire narrative.
Allegory gives an abstraction (death, justice, time) a concrete, coherent and usually developed form: the Grim Reaper with his scythe, Justice with her scales and blindfold. At the scale of a whole work, allegory becomes a double-reading narrative where each element of the literal level maps to an element of the symbolic one — Orwell's farm reads as an allegory of a betrayed revolution.
Unlike the symbol, which stays open, allegory tends toward term-for-term correspondence. Its strength is legibility; its danger, didacticism — when the reading key is too visible, the story becomes a demonstration.
Example
The Grim Reaper for death; Plato's cave for the human condition.