godan verb (-su), transitive verb
Used when someone deliberately tries to frighten another person into doing something or to assert power. Often implies verbal threats or aggressive posturing.
See also: 脅す (おどす)
彼はナイフで私を脅かした。
He threatened me with a knife.
上司にクビにすると脅かされた。
I was threatened by my boss with being fired.
godan verb (-su), transitive verb
Used when someone or something causes a sudden fright or surprise, often without malicious intent. Can be used for playful scares or unexpected loud noises.
後ろから急に肩を叩いて彼女を脅かした。
I startled her by suddenly tapping her on the shoulder from behind.
大きな音が子供たちを脅かした。
The loud noise frightened the children.