1. (

• monster ,
• fiend ,
• devil ,
• demon ,
• ogre ,

) a cruel wicked and inhuman person ;

2. (

• devil ,
• fiend ,
• demon ,
• daemon ,
• daimon

) an evil supernatural being ;

3. (

• fanatic ,
• fiend ,

) a person motivated by irrational enthusiasm (as for a cause); "A fanatic is one who can't change his mind and won't change the subject";