Etymology

Noun

1. A manuscript or document that has been erased or scraped clean, for reuse of the paper, parchment, vellum, or other medium on which it was written. Many historical texts have been recovered using ultraviolet light and other technologies to read the erased writing.
2. Monumental brasses that have been reused by engraving of the blank back side.
3. Circular features believed to be lunar craters that have been obliterated by later volcanic activity.
4. Geological features thought to be related to features or effects below the surface.
5. Memory that has been erased and re-written.
6. Something bearing the traces of an earlier, erased form.
   • 2005, Patrick Radden Keefe, Chatter:

     Miraculously, the Stasi's record of Garton Ash's years in Berlin remained intact, and in his extraordinary book The File he recalls going back to Berlin, sifting through the material, and piecing together those years for himself. The result is a palimpsest of memories, observations recorded by informants and agents, and the recollections in his own diaries at that time.

Verb

1. To scrape clean, as in parchment, for reuse.
2. On paper: to reuse, often by erasure or change of pen direction or color. Especially fueled by Earth Day.

   Typically refers to a multi-layered work, e.g.λ new ads covering old on a roadside sign.