Backboard

Back·board

Backboard

n.
  1. A board which supports the back when one is sitting;
  2. A board serving as the back part of anything, as of a wagon.
  3. A thin stuff used for the backs of framed pictures, mirrors, etc.
  4. A board attached to the rim of a water wheel to prevent the water from running off the floats or paddles into the interior of the wheel.
  5. A board worn across the back to give erectness to the figure.