Of, concerning, or characteristic of the devil; satanic.
Characterized by anger or spite; malicious:
The definition of cruel is someone or something that deliberately causes pain or suffering.
Severe and distressing:
Very cruel, evil, brutal, etc.
(Informal) Extremely bad
Not easy to persuade or convince; stubborn.
Causing or intending harm or evil; wicked:
Very wicked or cruel
Very unpleasant; detestable
Malicious; spiteful; mean
Find another word for fiendish. In this page you can discover 24 synonyms, antonyms, idiomatic expressions, and related words for fiendish, like: demoniac, diabolical, infernal, evil, cruel, wicked, atrocious, barbarous, demonic, devilish and difficult.