{computer term} A type of interrupt that is never masked. This is generally reserved for serious system errors and hardware faults.

Often abbreviated NMI.

This is not something the everyday end user ever sees directly, although whenever your computer crashes, it very likely either invoked an NMI -- or failed to do so properly.

see: interrupt handling

{computer worker slang} Something I've got to do right away, no matter what. Example: "Sorry, I gotta go pee *now* -- NMI!"