The Minimum Approach Break-off Height (MABH) is the lowest height above the ground, measured by radio-altimeter, such that if a missed approach is initiated without external references:
− in normal operation, the aircraft does not touch the ground during the procedure ;
− with an engine failure during a missed approach, it can be demonstrated that taking this failure probability, an accident is extremely improbable.
Apparently an Airbus thingy. Still wondering what it is though!