square or marketplace in an Italian town or city. The word is cognate with the French and English “place” and Spanish “plaza,” all ultimately derived from the Greek plateia, “broad street.” The most celebrated Italian piazza is that designed by Gian Lorenzo Bernini (Bernini, Gian Lorenzo) in front of St. Peter's Basilica, Rome. It is 650 feet (198 m) wide, being bounded on the sides by fourfold Tuscan colonnades.

The name became more widely used from the 16th to the 18th century, denoting any large open space with buildings around it. In 17th- and 18th-century England, long covered walks or galleries with roofs supported by columns were called piazzas, and, in the United States during the 19th century, piazza was another name for a veranda formed by projecting eaves.