A poncho is an article of clothing of ancient origin, a cloak made of a square or rectangle of cloth with a hole in the middle through which the wearer’s head protrudes. The original poncho, consisting of a rough, brightly colored, handloomed cloth, was worn in early cultures of Latin America. Ponchos are worn with the edges hanging either parallel or diagonally, forming a diamond shape. The style also was adapted as rain gear, made of waterproof material, and often hooded.

Source: Britannica