carelessness - the quality of not being careful or taking pains

dereliction, willful neglect, delinquency - 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"

laxity, laxness, remissness - the quality of being lax and neglectful