Fear is the feeling you get when you sense danger or threat. Your heart races, your muscles tense, and your mind becomes sharply focused on whatever seems dangerous. Fear is your body's alarm system, preparing you to either fight back, run away, or freeze in place.

Everyone experiences fear, from the moment a shadow moves unexpectedly in a dark room to facing a challenging test you didn't prepare for. Fear can be immediate and physical, like when you nearly fall off your bike, or it can be anticipatory, like worrying about giving a speech in front of your class next week.

Not all fears are equal. Some protect you: a healthy fear of traffic keeps you looking both ways before crossing the street. Other fears can hold you back unnecessarily, like being too scared to try out for a team you'd actually enjoy. People often say someone is fearless, but that usually means they act bravely despite feeling afraid, not that they never feel fear at all.

The word can also mean to expect something bad will happen. For example, “I fear we'll be late” means you think being late is likely. When something is described as fearsome, it means it causes fear in others, like a fearsome storm or a fearsome competitor.