Allah (ălˈə, äˈlə) [key], [Arab., = the God]. Derived from an old Semitic root refering to the Divine and used in the Canaanite El, the Mesopotamian ilu, and the biblical Elohim, the word Allah is used by all Arabic-speaking Muslims, Christians, Jews, and others. Allah, as a deity, was probably known in pre-Islamic Arabia. Arabic chronicles suggest a pre-Islamic recognition of Allah as a supreme God, with the three goddesses al-Lat, al-Uzza, and Manat as his "daughters." The Prophet Muhammad, declaring Allah the God of Abraham, demanded a return to a strict monotheism. Islam supplements Allah as the name of God with the 99 most beautiful names ( asma Allah al-husna ), understood as nondescriptive mnemonic guides to the Divine attributes.
See S. Friedlander, Ninety-Nine Names of Allah (1978).