Anglicized form of ALA AL-DIN. This is the name of a mischievous boy in one of the tales of 'The 1001 Nights'. He is trapped in a cave by a magician but escapes with the help of a genie.
Means "excellence of religion" from Arabic علاء ('ala) "excellence, elevation" combined with دين (din) "religion, faith". This was the name of several sultans of Delhi.