Difference between Nullification and Override

Nullification

Part of speech: noun

Definition: The act of nullifying; a rendering void and of no effect, or of no legal effect. removal

Override

Part of speech: noun

Definition: A mechanism, device or procedure used to counteract an automatic control.A royalty.A device for prioritizing audio signals, such that certain signals receive priority over others.

Part of speech: verb

Definition: to ride across or beyond something.to ride a horse too hard.to counteract the normal operation of something.

Example sentence: What happens when the guy who runs the reactor gets out of bed wrong or decides, for some reason, that he wants to override his instruction sheet some afternoon?