JALAL جلال
Being glorious or mighty. Zu ‘l-Jalal. “The Glorious One,” is an attribute of God. See Qur’an, Surah lv. 78: “Blessed be the name of thy Lord who is possessed of glory and honor.”
Al-Jalal is a term used by Sufi mystics to express that state of the Almighty which places Him beyond the understanding of His creatures. (‘Abdu ‘r-Razzaq’s Dictionary of Sufi Terms.)

Based on Hughes, Dictionary of Islam