Priority Zero
Noun · Slang & Abbreviations
Definitions
A level of urgency beyond the ordinary top priority, often reserved for the most severe incidents or blockers. In engineering slang, something called priority zero is expected to interrupt other plans immediately.
In plain English: An extremely urgent top-level priority that interrupts other work.
Example: "The data corruption report became priority zero as soon as they confirmed affected records were still being written, not just historically wrong."