MESJID, or MUSJEEED, ALI, a town of Asiatic Turkey, in the pashalic of Baghdad, is situated in a dry plain on the Euphrates, 90 miles S. by W. of Baghdad, and 28 S. of the ruins of Babylon. The town is well built, and surrounded by strong fortifications. The principal building is the mosque of Ali, containing the grave of the caliph of that name, visited by great numbers of pilgrims. Pop. about 6000.