partition board; divider plank
A board or plank used to separate spaces, such as in a room, storage area, or container.
I put a partition board in the closet to divide the space.
cargo separator board; dunnage plank
A board used inside a ship's hold to prevent cargo from shifting during transport.
In the ship's hold, partition boards are used to prevent the cargo from collapsing.
Compound of 仕切り (partition, division) and 板 (board, plank).