When you do the same thing again, or walk along the same path, you retread. You might love a writer's first book, but you'll still be disappointed if she only retreads the same plot in her second one.
You can, quite literally, retread your steps through the woods to find the beautiful grove of ferns you saw yesterday. You can also figuratively retread: "That candidate just retreads the same points over and over again!" When a car mechanic uses this word, it means "put new treads on a tire," or as a noun, the new surface of the tire itself. During World War I, retread was Australian slang for a "re-enlisted soldier."