Negligence is the failure to take enough care over something you are responsible for — a job, a child, a machine, a patient. In ordinary talk it is carelessness where care was owed. In law it is a sharp, formal word: a court may say someone caused harm by negligence even if they did not mean to hurt anyone. The sting is not “a bad thing happened,” but “you did not take the care that was reasonably expected.” It is heavier than a simple accident after you did take care. You will hear it from lawyers, news, insurance, and complaints more than from friends chatting.

疏忽。法律、保險、新聞裡台灣多說「過失」。