There are various synonyms that can be used for the term "scary guy" such as intimidating, frightening, creepy, menacing, terrifying, daunting, and eerie. These words describe a person who causes fear, discomfort, and unease. Intimidating refers to someone who appears strong and powerful, making others feel intimidated. Frightening is used to describe someone who induces fear or terror in others. Menacing implies someone who is continuously being threatening. Terrifying and daunting refer to someone causing extreme fear. Eerie is used to describe someone whose presence is unsettling and spooky. All these words can be used interchangeably with the term "scary guy" to convey the same meaning.