waterproof board; flood barrier; watertight panel
A board or panel used to prevent water entry, often in flood protection or construction. The cross-reference 止水板 is a near synonym.
See also: 止水板
We installed a flood barrier at the entrance in preparation for heavy rain.
This waterproof board helps prevent water from entering the basement.
Compound of 防水 (waterproof) + 板 (board, panel).