A down jacket is a type of outerwear that is filled with down feathers, usually from ducks or geese. It is designed to provide warmth and insulation in cold weather. The term 'down jacket' is often used interchangeably with the term 'PARKA, ' which is a five-letter word that is also used to describe this type of clothing. Parkas are typically longer than down jackets and have a hood, making them ideal for outdoor activities in cold climates.