Negligence means failing to take proper care or pay enough attention to something important, resulting in harm or problems. When someone is negligent, they don't do something they should have done, and their carelessness causes trouble.

A negligent babysitter might leave young children alone while scrolling through their phone, not noticing when one child wanders outside. A negligent driver might text while driving and cause an accident. A negligent pet owner might forget to give their dog water on a hot day. In each case, the person had a responsibility but failed to meet it through carelessness or inattention.

Negligence is different from an accident or honest mistake. When you accidentally knock over a glass of milk, that's not negligence. But if you're responsible for walking your neighbor's dog every day and you simply forget for three days in a row, leaving the dog without exercise or bathroom breaks, that's negligence. You had a duty to care for the animal, and you carelessly failed to do it.

The word appears often in legal contexts. If a building owner is negligent about fixing a broken staircase and someone gets hurt, they might be held legally responsible. Negligence involves both carelessness and consequences: the failure to act responsibly must actually cause some kind of harm or damage.