Anomaly
The industry's standard word for anything that did not go as planned, from a minor off-nominal reading to the total loss of a vehicle.
The word is doing real work, and it is worth reading carefully. 'Anomaly' is deliberately neutral: it covers a sensor reading slightly out of range and a rocket exploding, and it is used before the cause is known - which is legitimate engineering practice, not evasion. But it also blurs severity in public statements, so the useful question when you see it is always the same one: what was lost, and is the vehicle grounded?
Outcomes in our tracker are honest about this: of 350 missions, 185 have a confirmed success recorded, and only a handful carry a failure status - the remainder are upcoming or unconfirmed rather than problematic. Reading unconfirmed as failed is the most common mistake when interpreting a launch manifest.
A scrub, which is a launch called off before liftoff and is a normal, safe outcome, and a loss of mission, which is the unambiguous term for total failure.