Zab (Turkish: Zap suyu, Kurish: Zê, Persian: زاب; Zâb, Syriac: ܙܒܐ; Zawa) is the name given to two separate rivers that flow through Iran, Iraq and Turkey to become the two principal tributaries of the Tigris. The two rivers, named Greater Zab and Little Zab, were the basis of the ancient Assyrian civilisation. The name Zab is from the Persian word zehâb (زهاب), meaning "water flowing from the ground".