NajafPronunciation: /ˈnadʒaf/ (also an-Najaf)Definition of Najaf a city in southern Iraq, on the Euphrates; population 500,000 (est. 2003). It contains the shrine of Ali, the prophet Muhammad’s son-in-law, and is a holy city for the Shiite Muslims. Najaf in other Oxford dictionaries Definition of Najaf in the US English dictionary