Hood has several common meanings:

1. A covering for the head and neck that's usually attached to a jacket or sweatshirt. When it's raining or cold, you can pull up your hood to keep your head warm and dry. Medieval monks wore robes with hoods, and today hoodies are popular casual clothing.
2. The front part of a car that covers the engine. When a mechanic needs to check your car's engine, they pop open the hood.
3. A shortened form of neighborhood. When people talk about “the hood,” they mean the area where they live or grew up. Someone might say “I'm from the hood” to mean they're from a particular neighborhood.
4. A shortened form of hoodlum, meaning a troublemaker or petty criminal. This usage is somewhat old-fashioned.

The word can also mean covering something completely, like when fog hoods a mountain. Birds of prey like falcons sometimes wear small leather hoods during training to keep them calm.