tanbark

noun3

1. •
   The bark of the oak (or other trees) used as a source of tannin.
2. •
   The spent bark used as a ground covering.

   • Another circle of groats, crowning a temporary pathway of tanbark flung wide around the first two rings, provided dry footing for the rest of the guests. — 2004
3. •
   Woodchips, especially when used as a ground covering on children's playgrounds.