Dezful (dĕzfōlˈ) [key], city (1991 pop. 181,309), Khuzestan prov., SW Iran, on the Dez River, near the site of ancient Susa. It is the trade center for an irrigated farm region. Petroleum is produced nearby. The city gets its name, which means "citadel bridge," from a bridge built across the Dez by (according to legend) Shapur II. Dezful was a scene of rioting on the eve of the Iranian Revolution in 1978; it was attacked by Iraqi planes in the Iran-Iraq War. The city is also known as Dizful and Desful.