Raincoat

A raincoat or slicker is a waterproof or water-resistant coat worn to protect the body from rain. The term rain jacket is sometimes used to refer to raincoats that are waist length. A rain jacket may be combined with a pair of rain pants to make a rain suit.

Modern raincoats are often constructed of breathable, waterproof fabrics such as Gore-Tex or Tyvek and coated nylons. These fabrics allow some air to pass through, allowing the garment to 'breathe' so that sweat vapour can escape. The amount of pouring rain a raincoat can handle is sometimes measured in the unit millimeters, water gauge.

https://en.wikipedia.org/wiki/Raincoat