French word foudroyant comes from French foudroyer

Detailed word origin of foudroyant

Dictionary entry	Language	Definition
foudroyer	French (fra)	To devastate; to cause to be thunderstruck. To strike (of lightning).
foudroyant	French (fra)	(figurative) devastating. (figurative) rapid. (medicine) fulminant; fatal, deadly (coming on quickly and destructively).