A theodicy is a theory about why God allows evil to exist in the world. In other words, a theodicy contains speculations about God?s actual purposes in allowing evil to exist in the world. In order to be a successful theodicy, the purposes stated must be wholly consistent with the notion that God is all-loving. So what is called for is an explanation of the purposes that a loving God might have in permitting evil to exist.
The word is taken from the title of a work that supplied one theodicy, namely that this is TheBestOfAllPossibleWorlds?: the TheoDicee? by GottfriedLeibniz. See also TheProblemOfEvil.