Frightened means feeling sudden fear or alarm because of something threatening or dangerous. When you're frightened, your heart might pound, your hands might shake, and you might freeze in place or run away. You could be frightened by a loud crash in the night, by a snake on the hiking trail, or by the sudden appearance of something unexpected.

Being frightened is a natural response that helps keep us safe. When early humans saw a predator, being frightened helped them react quickly to danger. Today, you might feel frightened during a scary movie or when you're lost in an unfamiliar place.

The word suggests more intensity than just being worried or nervous. You might be nervous about a test, but frightened by a close call while riding your bike. Animals can be frightened too: a deer becomes frightened by sudden movement and bolts into the forest, or a cat gets frightened by a vacuum cleaner and hides under the bed.

Someone who frightens easily might jump at small noises or feel scared more often than others. Frightening describes something that causes fear, like a frightening thunderstorm or a frightening scene in a book.