DAU : DAU Glossary of Defense Acquisition Acronyms and Terms
A characteristic that analysis indicates is likely, if defective, to create or increase a hazard to human safety, or to result in failure of a system to perform a required function.
See Also:
Key Characteristic. Product Characteristic
Alternate Definitions:

Model-Based Characteristics (MBC) - A Product Characteristic, which is supplemented by a criticality classification augmentation.