means A waterproof or water-resistant coat worn to keep your body and clothes dry in the rain.

from A plain English compound, literally "rain" + "coat," assembled in the 19th century as waterproofed garments became practical. "Rain" descends from Old English "regn," a word shared across the Germanic languages, while "coat" came into Middle English from Old French "cote," a tunic or outer garment. The thing itself owes much to Charles Macintosh, whose rubberized fabric made the "mackintosh" a British byword for the same idea.