B

n. A board which supports the back when one is sitting; specifically, the board athwart the after part of a boat. A board serving as the back part of anything, as of a wagon. A thin stuff used for the backs of framed pictures, mirrors, etc. 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. A board worn across the back to give erectness to the figure.