I just realized that this Word of the Week never got posted. So we're back-posting to make sure we have a Word of the Week #121.
scurf - [SKURF] - noun
1. The scales or small shreds of epidermis that are continually exfoliated from the skin.
2. Any scaly matter or incrustation on a surface.
A desperate vacuum cleaner salesman tried to scare me into buying his freakishly expensive product with tales of the horrible amount of scurf mounding up in our mattresses. I told him that I grew up in a farming community, and there were a whole lot worse things to be sleeping on. Trust me.