Negligent Discharge
An unintentional discharge caused by violation of one of the safety rules.
Also: ND, AD
A negligent discharge is an unintentional firing caused by user error — bad trigger discipline, failure to clear, dropping the gun against a surface, a finger inside the trigger guard during reholstering. The term accidental discharge (AD) is sometimes used interchangeably, but most instructors prefer negligent because the cause is almost always a rule violation, not a mechanical failure.