Frightening means causing fear or alarm. When something is frightening, it makes you feel scared, anxious, or worried about what might happen. A frightening movie might make you jump in your seat or peek through your fingers. A frightening experience, like getting lost in a crowded place, can leave your heart pounding even after it's over.

What makes something frightening varies from person to person. Thunder might be frightening to a young child but exciting to a storm chaser. The same roller coaster that seems frightening from the ground might feel thrilling once you're riding it. Sometimes we even enjoy frightening things in safe contexts: people read scary stories or visit haunted houses because being a little frightened can be fun when you know you're actually safe.

The word can describe physical danger (a frightening growl from a strange dog) or emotional situations (the frightening feeling before giving a presentation). Notice that frightening is different from startling, which just means sudden and surprising. Something frightening creates a deeper, more lasting sense of fear or dread. When meteorologists warn of frightening weather conditions, they mean conditions serious enough to make people genuinely worried about their safety.