What is Board Foot?

Legal Definition
The board-foot is a specialized unit of measure for the volume of lumber in the United States and Canada. It is the volume of a one-foot length of a board one foot wide and one inch thick.

Board-foot can be abbreviated FBM (for "foot, board measure"), BDFT, or BF. Thousand board-feet can be abbreviated as MFBM, MBFT, or MBF. Similarly, million board-feet can be abbreviated as MMFBM, MMBFT, or MMBF.
-- Wikipedia
Legal Definition
A piece of lumber that is 12x12x1 inch. It is the volume of lumber needed to get 1/12 F3. AKA board measure, foot board measure, or super foot. Refer to cord.