A trope that says one thing is another in order to transfer the qualities of the source onto the target — the world is a stage, time is money, life a road. Metaphor runs through the entire literary record (Homer, Shakespeare, Donne, Toni Morrison) and equally through political oratory, ad copy, and ordinary speech, where it has so settled in (leg of the table, running for office) that the figure stops being felt as one. It is the figure most often confused with simile and the parent of allegory, conceit, catachresis, and personification.
Etymology
Gk. meta "across, beyond" + pherein "to carry" — to carry meaning across from one thing to another.