frighten
v.v. to make someone feel afraid or scared. You use this when something sudden or dangerous causes a person to feel fear.
v. to cause fear or apprehension in someone. Transitive — requires a direct object, typically a person or animal.
The loud thunder might frighten the dog.
The sudden movement in the bushes was enough to frighten the hikers, who stopped immediately to look for bears.
While the ghost stories were intended to entertain the children, the vivid descriptions of the haunted attic began to frighten them more than their parents had anticipated.
From Middle English *frightenen, equivalent to fright + -en.
The verb is transitive and takes a direct object. It is often used in the passive voice ('to be frightened') followed by the preposition 'of' or 'by'.
The movie frightened to meThe movie frightened meFrighten is a transitive verb and takes a direct object without the preposition 'to'.