a tendency to be negligent and uncaring; "he inherited his delinquency from his father"; "his derelictions were not really intended as crimes"; "his adolescent protest consisted of willful neglect of all his responsibilities"
If a building or a piece of land is in a state of dereliction, it is deserted or abandoned. The previous owners had rescued the building from dereliction
Dereliction of duty is deliberate or accidental failure to do what you should do as part of your job. He pleaded guilty to wilful dereliction of duty. = negligence