Anything that's receding is fading or moving backwards. A receding shoreline often forms around a lake during a drought — as the lake grows smaller, the edge of the shore slowly moves back.
You'll often find the adjective receding describing a man's hair in the process of very gradually going bald: "He's a tall guy with a receding hairline and glasses." As a noun, receding means a quality or act of disappearing or fading away. The receding of your childhood home in the rearview mirror is a good metaphor for growing up and moving on.