board 
(bôrd)
(bôrd)n.
1.
a. A long flat slab of sawed lumber; a plank.
b. A long flat slab of another material, used as a structural member.
2. A flat, rigid, often rectangular piece of material used as a surface upon which to work: a cutting board; an ironing board.
3. A flat piece of rigid material designed to display information, especially:
a. A blackboard.
b. A bulletin board.
c. A scoreboard.
d. A toteboard.
4. Sports
a. A flat piece of material designed or equipped to be ridden as a sport, especially a snowboard, skateboard, or surfboard.
b. A diving board.
c. A backboard.
5. A flat, rigid piece of material on which a game is played, such as a checkerboard or chessboard.
6.
a. A table at which official meetings are held; a council table.
b. An organized body of administrators or investigators: a board of trustees; a board of directors.
7.
a. A table, especially one set for serving food.
b. Food or meals considered as a whole: board and lodging.
8. boards
a. Sports The wooden structure enclosing an area for skating, such as the ice on which hockey is played, or enclosing a playing area, as for indoor soccer.
b. A theater stage.
9. Basketball A rebound.
10.
a. An electrical-equipment panel.
b. Computers A circuit board.
11. Nautical
a. The side of a ship.
b. A leeboard.
c. A centerboard.
12. Obsolete A border or edge.
v. board·ed, board·ing, boards
v.tr.
1. To cover or close with boards: board up a broken window.
2.
a. To furnish with meals in return for pay.
b. To house where board is furnished: board a horse at a stable.
3.
a. To enter or go aboard (a vehicle or ship).
b. To allow (passengers) on board.
c. Nautical To come alongside (a ship).
4. Sports To force (an opposing hockey player) into the boards with a body check.
5. Obsolete To approach.
v.intr.
Idioms: 1. To receive meals or food and lodging as a paying customer.
2. Sports To use a snowboard, skateboard, surfboard, or similar item.
across the board
So as to affect or include all people, classes, or categories: raised taxes across the board.
on board
1. Aboard.
2. Ready to participate or be included; amenable: The entire class was on board for the excursion to the park.
[Middle English bord, from Old English.]