Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun fiend

3 senses of fiend

Sense 1
monster, fiend, devil, demon, ogre -- (a cruel wicked and inhuman person)
       => unpleasant person, disagreeable person -- (a person who is not pleasant or agreeable)

Sense 2
devil, fiend, demon, daemon, daimon -- (an evil supernatural being)
       => evil spirit -- (a spirit tending to cause harm)

Sense 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"--Winston Churchill)
       => enthusiast, partisan, partizan -- (an ardent and enthusiastic supporter of some person or activity)