Final answer:
The antonym of 'foreordained' is 'spontaneous,' indicating an unplanned, naturally occurring event as opposed to something predetermined by fate or divine will.
Step-by-step explanation:
The antonym of "foreordained" is spontaneous. This is because foreordained events are pre-established by divine will or fate, meaning they are predetermined and not happening by chance or without apparent or deliberate cause. On the other hand, spontaneous events occur without pre-planning, and they are driven by natural tendencies without the need for continuous external energy, often resulting in a sudden release of energy and a move to a more stable state.