A nightlight is a small, dim light that stays on through the night to make a dark room less scary or easier to navigate. Many children use nightlights in their bedrooms so they can see a little bit if they wake up in the middle of the night, making the darkness feel less overwhelming. Parents often plug nightlights into hallway outlets so family members can find their way to the bathroom without turning on bright overhead lights that might wake everyone up.

Nightlights give off just enough glow to see shapes and avoid bumping into furniture, but they're dim enough that they won't keep you awake. Some nightlights plug directly into wall outlets, while others are battery-powered and can be placed anywhere. Modern nightlights might have motion sensors that turn on automatically when someone walks by, or timers that shut off after a few hours.

The word can also describe any soft, persistent light at night. You might say the moon provides a nightlight for nocturnal animals, or that streetlamps serve as nightlights for a quiet neighborhood.