A metaphysical term meaning ‘existence’, employed by philosophically-inclined thinkers such as al-Fārābī (d. ca. 950), Ibn Rushd (d. 1198), al-Suhrawardī and Mullā Ṣadrā (d. 1050/1640). According to Ibn Sina (d. 1037), God is the wājib al-wujud (‘the necessary existent’ or ‘the one whose essence is to exist’). Sufis use the term wujūd in different ways. Ibn al-ʿArabī (d. 638/1240) is regarded as the father of the concept of waḥdat al-wujūd (the unity of being).