WordWeight : Weighing the Words

Pronunciation : Back"board`
Part of Speech : n.
Etymology : [2nd back, n. + board.]
Definition : 1. A board which supports the back wen one is sitting;

Note: specifically, the board athwart the after part of a boat.

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 paddies into the interior of the wheel. W. Nicholson.

5. A board worn across the back to give erectness to the figure. Thackeray.
Source : Webster's Unabridged Dictionary, 1913