Scare and Intimidate are similar, but not the same.

Scare implies directly frightening someone. A ghost, for example, scares a person.

Intimidation is different. Intimidating someone is threatening them to make them do what you want. So, a mobster would intimidate you into doing his work for him.

Fear is not a verb, but a noun. You cannot "fear" someone, but someone can be "afraid" (which is the adjective form of fear.)