Home › Words › F › floodboardfloodboardfloodboard · noun — A waterproof board placed over an opening, such as a door or window, to prevent floodwater from entering.Definition from Wiktionary (CC BY-SA 3.0).EtymologyFrom flood + board.nounA waterproof board placed over an opening, such as a door or window, to prevent floodwater from entering.Definitions & examples from Wiktionary (CC BY-SA 3.0).